Gastrointestinal disease

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Chapter 6 Gastrointestinal disease

Gastrointestinal symptoms and signs

Vomiting

Many gastrointestinal (and non-gastrointestinal) conditions are associated with vomiting (Table 6.1). This is controlled by a complex reflex involving central neural control centres located in the lateral reticular formation of the medulla which are stimulated by the chemoreceptor trigger zones (CTZs) in the floor of the fourth ventricle, and also by vagal afferents from the gut. The central zones are directly stimulated by toxins, drugs, motion sickness and metabolic disturbances. Raised intracranial pressure has a direct effect on the vomiting centre leading to vomiting. Luminal toxins, inflammation and mechanical obstruction are local GI causes of vomiting.

Table 6.1 Causes of vomiting: some examples

Nausea is a feeling of wanting to vomit, often associated with autonomic effects including salivation, pallor and sweating. It often precedes actual vomiting. Retching is a strong involuntary unproductive effort to vomit associated with abdominal muscle contraction but without expulsion of gastric contents through the mouth.

Faeculent vomit suggests low intestinal obstruction or the presence of a gastrocolic fistula.

Haematemesis is vomiting fresh or altered blood (‘coffee-grounds’) (see p. 254).

Early-morning nausea and vomiting is seen in pregnancy, alcohol dependence and some metabolic disorders (e.g. uraemia).

Persistent nausea alone is often stress-related and is not due to gastrointestinal disease.

Flatulence

This term describes excessive wind. It is used to indicate belching, abdominal distension, gurgling and the passage of flatus per rectum. Swallowing air (aerophagia) is described on page 296. Some of the swallowed air passes into the intestine where most of it is absorbed, but some remains to be passed rectally. Colonic bacterial breakdown of non-absorbed carbohydrate also produces gas. Rectal flatus thus consists of nitrogen, carbon dioxide, hydrogen and methane. It is normal to pass rectal flatus up to 20 times/day. Causes of increased gas production and intake include high-fibre diet and carbonated drinks.

Abdominal pain

Pain is stimulated mainly by the stretching of smooth muscle or organ capsules. Severe acute abdominal pain can be due to a large number of gastrointestinal conditions, and normally presents as an emergency (see p. 298). An apparent ‘acute abdomen’ can occasionally be due to referred pain from the chest, as in pneumonia or to metabolic causes, such as diabetic ketoacidosis or porphyria.

Check:

Examination of the abdomen

Examination of the rectum and sigmoid colon

A digital examination of the rectum should be performed in all patients with a change in bowel habit, rectal bleeding and prior to proctoscopy or sigmoidoscopy.

Investigations

Routine haematology and biochemistry, followed by endoscopy and radiology, are the principal investigations. The investigation of small bowel disease is discussed in more detail on page 267. Manometry is mainly used in oesophageal disease (see p. 237) and anorectal disorders (see p. 286).

Endoscopy

Video endoscopes have replaced fibreoptic instruments and relay colour images to a high definition television monitor. The tip of the endoscope can be angulated in all directions. Channels in the instrument are used for air insufflation, water injection, suction, and for the passage of accessories such as biopsy forceps or brushes for obtaining tissue, snares for polypectomy and needles for injection therapies. Permanent photographic or video records of the procedure can be obtained.

image Oesophagogastroduodenoscopy (OGD, ‘gastroscopy’) is the investigation of choice for upper GI disorders with the possibility of therapy and mucosal biopsy. Findings include reflux oesophagitis, gastritis, ulcers and cancer. Therapeutic OGD is used to treat upper GI haemorrhage and both benign and malignant obstruction. Relative contraindications include severe chronic obstructive pulmonary disease, a recent myocardial infarction, or severe instability of the atlantoaxial joints. The mortality for diagnostic endoscopy is 0.001% with significant complications in 1 : 10 000, usually when performed as an emergency (e.g. GI haemorrhage).

image Colonoscopy allows good visualization of the whole colon and terminal ileum. Biopsies can be obtained and polyps removed. Benign strictures can be dilated and malignant strictures stented. The success rate for reaching the caecum should be at least 90% after training. Cancer, polyps and diverticular disease are the commonest significant findings. Perforation occurs in 1 : 1000 examinations but this is higher (up to 2%) after polypectomy (see Practical Box 6.2).

image Balloon enteroscopy, either double or single balloon, can examine the small bowel from the duodenum to the ileum using specialized enteroscopes in expert centres.

image Capsule endoscopy is used for the evaluation of obscure GI bleeding (after negative gastroscopy and colonoscopy) and for the detection of small bowel tumours and occult inflammatory bowel disease. It should be avoided if strictures are suspected.

image Practical Box 6.2

Gastroscopy and colonoscopy

Imaging

Full clinical information must be provided before the examination, and ideally, the images obtained should be reviewed with the radiologist to aid interpretation. The optimal technique to be used will depend on local expertise.

Plain X-rays of the chest and abdomen are chiefly used in the investigation of an acute abdomen. Interpretation depends on analysis of gas shadows inside and outside the bowel. Plain films are particularly useful where obstruction or perforation is suspected, to exclude toxic megacolon in colitis and to assess faecal loading in constipation. Calcification may be seen with gall bladder stones and in chronic pancreatitis, though CT is more sensitive for both.

Ultrasound involves no radiation and is the first-line investigation for abdominal distension, e.g. ascites, mass or suspected inflammatory conditions. It can show dilated fluid-filled loops of bowel in obstruction, and thickening of the bowel wall. It can be used to guide biopsies or percutaneous drainage. In an acute abdomen, ultrasound can diagnose cholecystitis, appendicitis, enlarged mesenteric glands and other inflammatory conditions.

Computed tomography involves a significant dose of radiation (approximately 10 millisieverts). Modern multislice fast scanners and techniques involving intraluminal and intravenous contrast enhance diagnostic capability. Intraluminal contrast may be positive (Gastrografin or Omnipaque) or negative (usually water). The bowel wall and mesentery are well seen after intravenous contrast especially with negative intraluminal contrast. Clinically unsuspected diseases of other abdominal organs are quite often also revealed (Fig. 6.5a).

Magnetic resonance imaging. MRI uses no radiation and is particularly useful in the evaluation of rectal cancers and abscesses and fistulae in the perianal region. It is also useful in small bowel disease and in hepatobiliary and pancreatic disease.

Positron emission tomography (PET) relies on detection of the metabolism of fluorodeoxyglucose. It is used for staging oesophageal, gastric and colorectal cancer and in the detection of metastatic and recurrent disease. PET/CT adds additional anatomical information.

Contrast studies

image Barium swallow examines the oesophagus and proximal stomach. Its main use is for investigating dysphagia.

image Double-contrast barium meal examines the oesophagus, stomach and duodenum. Barium is given to produce mucosal coating and effervescent granules producing carbon dioxide in the stomach create a double contrast between gas and barium. This test has a high accuracy for the detection of significant pathology – ulcers and cancer – but requires good technique. Gastroscopy is a more sensitive test and enables biopsy of suspicious areas.

image Small bowel meal or follow-through specifically examines the small bowel. Ingested barium passes through the small bowel into the right colon. The fold pattern and calibre of the small bowel are assessed. Specific views of the terminal ileum can be obtained and are used to identify early changes in patients with suspected Crohn’s disease.

image Small bowel enema (enteroclysis) is an alternative specific technique for small bowel examination. A tube is passed into the duodenum and a large volume of dilute barium is introduced. It is particularly used to demonstrate strictures or adhesions when there is suspicion of intermittent obstruction. Generally, this has been replaced by MR enteroclysis.

image Barium enema examines the colon and is used for altered bowel habit. Colonoscopy and CT colonography have largely replaced this examination for rectal bleeding, polyps and inflammatory bowel disease.

image Absorbable water-soluble (Gastrografin or Omnipaque) contrast agents should be used in preference to barium when perforation is suspected anywhere in the gut.

Radioisotopes

Radionuclides are used to a varying degree depending on availability and expertise. Some more common indications and techniques:

image Detect urease activity of Helicobacter pylori13C urea breath test (see p. 249)

image Assess oesophageal reflux – gamma camera scan after oral [99mTc]technetium-sulphur colloid

image Measure rate of gastric emptying – sequential gamma camera scans after oral [99mTc]technetium-sulphur colloid or 111In-DTPA (indium-labelled diethylene triamine penta-acetic acid)

image Demonstrate a Meckel’s diverticulum – gamma camera scan after i.v. [99mTc]pertechnetate, which has affinity for gastric mucosa

image Assess extent of inflammation and presence of inflammatory collections in inflammatory bowel disease – gamma camera scan after i.v. 99mTc-HMPAO (hexamethylpropylene amine oxime) labelled white cells

image Evaluate neuroendocrine tumours and their metastases – gamma camera scan after i.v. radiolabelled octreotide or MIBG (meta-iodobenzylguanidine)

image Assess obscure gastrointestinal bleeding – gamma camera abdominal scan after i.v. injection of red cells labelled with 99mTc (only useful if the bleeding is >2 mL/min)

image Measure albumin loss in the stools (in protein-losing enteropathy) – following albumin labelled in vivo with i.v. 51CrCl3. This test has been replaced by the measurement of the intestinal clearance of α1 antitrypsin

image Assess bile salt malabsorption (in patients with unexplained diarrhoea) – gamma camera scan to measure both isotope retention and faecal loss of orally administered 75selenium-homocholic acid taurine (SeHCAT) (see p. 293)

image Detect bacterial overgrowth in the small bowel – measure 14CO2 in breath following oral 14C glycocholic acid.

The mouth

The oral cavity extends from the lips to the pharynx and contains the tongue, teeth and gums. Its primary functions are mastication, swallowing and speech. Problems in the mouth are extremely common and, although they may be trivial, they can produce severe symptoms. Poor dental hygiene is often a factor.

The salivary glands

Excessive salivation (ptyalism) may occur prior to vomiting or be secondary to other intraoral pathology. It can be psychogenic.

Dry mouth (xerostomia) can result from a variety of causes:

The principles of management are to preserve what flow remains, stimulate flow and replace saliva (glycerine and lemon mouthwash and artificial saliva).

The pharynx and oesophagus

Structure and physiology

The oesophagus is a muscular tube approximately 20 cm long that connects the pharynx to the stomach just below the diaphragm. Its only function is to transport food from the mouth to the stomach. In the upper portion of the oesophagus, both the outer longitudinal layer and inner circular muscle layers are striated. In the lower two-thirds of the oesophagus, including the thoracic and abdominal parts containing the lower oesophageal sphincter, both layers are composed of smooth muscle.

The oesophagus is lined by stratified squamous epithelium, which extends distally to the squamocolumnar junction where the oesophagus joins the stomach, recognized endoscopically by a zig-zag (‘Z’) line, just above the most proximal gastric folds.

The oesophagus is separated from the pharynx by the upper oesophageal sphincter (UOS), which is normally closed due to tonic activity of the nerves supplying the cricopharyngeus. The lower oesophageal sphincter (LOS) consists of a 2–4 cm zone in the distal end of the oesophagus that has a high resting tone and, assisted by the diaphragmatic sphincter, is largely responsible for the prevention of gastric reflux.

Swallowing

During swallowing, the bolus of food is voluntarily moved from the mouth to the pharynx. This process is mediated by a complex reflex involving a swallowing centre in the dorsal motor nucleus of the vagus in the brainstem. Once activated, the swallowing centre neurones send pre-programmed discharges of inhibition followed by excitation to the motor nuclei of the cranial nerves. This results in initial relaxation, followed by distally progressive activation of neurones to the oesophageal smooth muscle and LOS. Pharyngeal and oesophageal peristalsis mediated by this swallowing reflex causes primary peristalsis. Secondary peristalsis arises as a result of stimulation by a food bolus in the lumen, mediated by a local intra-oesophageal reflex. Tertiary contractions indicate pathological non-propulsive contractions resulting from aberrant activation of local reflexes within the myenteric plexus.

The smooth muscle of the thoracic oesophagus and lower oesophageal sphincter is supplied by vagal autonomic motor nerves consisting of extrinsic preganglionic fibres and intramural postganglionic neurones in the myenteric plexus (Fig. 6.6). There are parallel excitatory and inhibitory pathways.

Symptoms of oesophageal disorders

Major oesophageal symptoms are:

Table 6.3 Causes of dysphagia

Investigations available for oesophageal disorders

image Barium swallow and meal.

image Oesophagoscopy.

image Manometry (Fig. 6.7) is performed by passing a catheter through the nose into the oesophagus and measuring the pressures generated within the oesophagus. It is used to assess oesophageal motor activity. It is not a primary investigation and should be performed only when the diagnosis has not been achieved by history, barium radiology or endoscopy. Recordings are usually made over a short time period, or much more rarely for up to 24 h. High resolution manometry has superseded conventional manometry and the greater concentration of pressure sensors enables the identification of a wider range of abnormalities of oesophageal function with a greater diagnostic accuracy.

image pH monitoring – 24-hour ambulatory monitoring uses a pH-sensitive probe positioned in the lower oesophagus and is used to identify acid reflux episodes (pH <4). Catheter and implantable sensors are available; both are insensitive to alkali. Although only 5–10% of recorded acid reflux episodes are perceived by the patient, pH is a valuable means of correlating episodes of acid reflux with patient’s symptoms.

image Impedance uses a catheter to measure the resistance to flow of ‘alternating current’ in the contents of the oesophagus. Combined with pH it allows assessment of acid, weakly acid, alkaline and gaseous reflux, which is helpful in understanding the symptoms that are produced by a non-acid reflux. Treatment is, however, still difficult in these conditions.

Gastro-oesophageal reflux disease (GORD)

Pathophysiology

Between swallows, the muscles of the oesophagus are relaxed except for those of the sphincters. The LOS remains closed due to the unique property of the muscle and relaxes when swallowing is initiated. Transient Lower Oesophageal Sphincter Relaxations (TLESRs) are part of normal physiology, but occur more frequently in GORD patients (Fig. 6.8).

Small amounts of gastro-oesophageal reflux are normal. The lower oesophageal sphincter (LOS) in the distal oesophagus is in a state of tonic contraction and relaxes transiently to allow the passage of a food bolus (see p. 229). Sphincter pressure also increases in response to rises in intra-abdominal and intragastric pressures.

Other antireflux mechanisms involve the intra-abdominal segment of the oesophagus which acts as a flap valve. In addition, the mucosal rosette formed by folds of the gastric mucosa and the contraction of the crural diaphragm at the LOS acting like a pinchcock, prevent acid reflux. A large hiatus hernia can impair this mechanism. The oesophagus is also normally rapidly ‘cleared’ of refluxate by secondary peristalsis, gravity and salivary bicarbonate.

The clinical features of reflux occur when the antireflux mechanisms fail, allowing acidic gastric contents to make prolonged contact with the lower oesophageal mucosa. The sphincter relaxes transiently independently of a swallow after meals and this is the cause of almost all reflux in normals and about two-thirds in GORD patients.

Clinical features

Heartburn is the major feature. Factors associated with GORD are shown in Table 6.4.

Table 6.4 Factors associated with gastro-oesophageal reflux

The burning is aggravated by bending, stooping or lying down which promote acid exposure, and may be relieved by oral antacids. The patient complains of pain on drinking hot liquids or alcohol.

The correlation between heartburn and oesophagitis is poor. Some patients have mild oesophagitis but severe heartburn; others have severe oesophagitis without symptoms, and may present with a haematemesis or iron deficiency anaemia from chronic blood loss. Psychosocial factors are often determinants of symptom severity. Many patients erroneously ascribe their symptoms to their hiatus hernia (Box 6.2) but the symptoms are due to reflux.

Differentiation of cardiac and oesophageal pain can be difficult; 20% of cases admitted to a coronary care unit have GORD (Box 6.3). In addition to the clinical features, a trial of a proton pump inhibitor (PPI) is always worthwhile and if symptoms persist, ambulatory pH and impedance monitoring should be performed.

Regurgitation of food and acid into the mouth occurs, particularly on bending or lying flat. Aspiration pneumonia is unusual without an accompanying stricture, but cough and asthma can occur and respond slowly (1–4 months) to a PPI.

Diagnosis and investigations

The clinical diagnosis can usually be made without investigation. Unless there are alarm signs, especially dysphagia (see p. 229), patients under the age of 45 years can safely be treated initially without investigations. If investigation is required, there are two aims:

image Assess oesophagitis and hiatal hernia by endoscopy. If there is oesophagitis (Fig. 6.9) or Barrett’s oesophagus (see p. 241), reflux is confirmed.

image Document reflux by intraluminal monitoring (Fig. 6.10). 24-hour intraluminal pH monitoring or impedance combined with manometry is helpful if there is no response to PPI and should always be performed to confirm reflux before surgery. Excessive reflux is defined as a pH <4 for >4% of the time. There should also be a good correlation between reflux (pH <4.0) and symptoms. It is also helpful to assess oesophageal dysmotility as a potential cause of the symptoms.

Treatment

Approximately half of patients with reflux symptoms in primary care can be treated successfully with simple antacids, loss of weight and raising the head of the bed at night. Precipitating factors should be avoided, with dietary measures, reduction in alcohol and caffeine consumption and cessation of smoking. These measures are simple to say but difficult to carry out, though they are useful in mild disease in compliant patients.

Drugs

Alginate-containing antacids (10 mL three times daily) are the most frequently used ‘over the counter’ agents for GORD. They form a gel or ‘foam raft’ with gastric contents to reduce reflux. Magnesium-containing antacids tend to cause diarrhoea while aluminium-containing compounds may cause constipation.

The dopamine antagonist prokinetic agents metoclopramide and domperidone are occasionally helpful as they enhance peristalsis and speed gastric emptying, but there is little data to substantiate this.

H2-receptor antagonists (e.g. cimetidine, ranitidine, famotidine and nizatidine) are frequently used for acid suppression if antacids fail as they can often be obtained over the counter.

Proton pump inhibitors (PPIs: omeprazole, rabeprazole, lansoprazole, pantoprazole, esomeprazole) inhibit gastric hydrogen/potassium-ATPase. PPIs reduce gastric acid secretion by up to 90% and are the drugs of choice for all but mild cases. Most patients with GORD will respond well, but this is only 20–30% of patients presenting with heartburn. Patients with severe symptoms may need twice-daily PPIs and prolonged treatment, often for years. Once oesophageal sensitivity has normalized, a lower dose, e.g. omeprazole 10 mg, may be sufficient for maintenance. The patients who do not respond to a PPI are sometimes described as having non-erosive reflux disease (NERD) (Fig. 6.11), when the endoscopy is normal. These patients are usually female and often the symptoms are functional, although a small group have a hypersensitive oesophagus, giving discomfort with only slight changes in pH. Isomers of some of the original PPIs (e.g. dexlansoprazole) have the benefit of more effective gastric acid inhibition over a longer time period as their metabolism to the active metabolite is slower.

Complications

Barrett’s oesophagus

Barrett’s oesophagus is a condition in which part of the normal oesophageal squamous epithelium is replaced by metaplastic columnar mucosa to form a segment of ‘columnar-lined oesophagus’ (CLO). It is a complication of gastro-oesophageal reflux disease and there is almost always a hiatus hernia present.

Diagnosis and classification. The diagnosis is made by endoscopy showing proximal displacement of the squamocolumnar mucosal junction and biopsies demonstrating columnar lining above the proximal gastric folds; intestinal metaplasia is no longer a requirement of the British Society of Gastroenterology definition, but is central to the American College of Gastroenterology guidelines. Barrett’s oesophagus may be seen as a continual circumferential sheet, or finger-like projections extending upwards from the squamocolumnar junction or as islands of columnar mucosa interspersed in areas of residual squamous mucosa. The Prague Classification (Fig. 6.12) is used for recording the endoscopic distribution, stating both the length of circumferential CLO (C measurement) as well as the maximum length (M measurement), the distance from the top of the gastric folds to the most proximal tongue of the columnar mucosa.

Central obesity increases the risk of Barrett’s by 4.3 times. Long segment (>3 cm) and short segment (<3 cm) Barrett’s is found respectively in 5% and 15% of patients undergoing endoscopy for reflux symptoms. It is also often found incidentally in endoscoped patients without reflux symptoms. Barrett’s is commonest in middle-aged obese men. The major concern is that approximately 0.12–0.5% of Barrett’s patients develop oesophageal adenocarcinoma per year, the majority, probably, through a gradual transformation from intestinal metaplasia to low-grade then high-grade dysplasia, before invasive adenocarcinoma. Barrett’s increases the chance of developing oesophageal adenocarcinoma 30- to 50-fold in early studies but a recent study showed the risk to be much lower.

In the absence of high quality trial evidence, 2-yearly gastroscopies are recommended by some, at which time biopsies from all four quadrants (every 1–2 cm) of the CLO are taken, as well as biopsies from macroscopically abnormal areas. High-grade dysplasia (HGD) is usually associated with endoscopically visible nodules or ulceration which are optimally visualized with a high definition endoscope. Chromo-endoscopy (the topical application of stains or pigments via the endoscope), narrow band and autofluorescence imaging may aid the diagnosis of dysplasia and carcinoma.

Endoscopic screening and surveillance in Barrett’s oesophagus. Because of the poor correlation between Barrett’s oesophagus and symptoms screening ‘at risk’ populations has not been shown to reduce the risk of oesophageal adenocarcinoma and is not recommended. As yet, there is no good evidence base for endoscopic surveillance of patients with established Barrett’s oesophagus; however, a randomized control trial is currently underway. The global consensus currently favours 2-yearly screening (in the absence of dysplastic change) with endoscopic technology improving the detection of premalignant lesions and enabling their removal with either endoscopic mucosal resection (EMR) or endoscopic submucosal dissection, therefore preventing surgical oesophagectomy. However, recent data, which have shown a reduction in the incidence of Barrett’s oesophagus, have cast doubt on this approach.

If low-grade dysplasia is found on endoscopic surveillance, a repeat endoscopy with quadrantic biopsies every 1 cm is usually performed within 6 months, while on high-dose proton pump inhibition. Long-term surveillance in this group is controversial.

If high-grade dysplasia is found, this is usually in the context of an endoscopically visible lesion which, if nodular, is removed by endoscopic mucosal resection for more accurate histological staging. If high-grade dysplasia is detected in the absence of any endoscopically visible lesion high-dose proton pump inhibition is started and repeat biopsies taken within 3 months. Endoscopic ultrasound is frequently used to more accurately stage this patient group to exclude cancer and associated significant lymphadenopathy.

Radiofrequency ablation (RFA) has superseded photodynamic therapy as the technique of choice for endoscopic treatment of dysplasia within Barrett’s segments following removal of any nodular lesions, returning the oesophagus to squamous lining. The benefit of RFA in low-grade dysplasia is currently under evaluation.

Motility disorders

Achalasia

Achalasia is characterized by oesophageal aperistalsis and impaired relaxation of the lower oesophageal sphincter.

Treatment

All current forms of treatment for achalasia are palliative. Drug therapy rarely produces satisfactory or durable relief; nifedipine (20 mg sublingually) or sildenafil can be tried initially.

Endoscopic and surgical therapies are equally effective. Endoscopic dilatation of the LOS using a hydrostatic balloon under X-ray control weakens the sphincter and is successful initially in 80% of cases. About 50% of patients require a second or third dilatation in the first 5 years. There is a low but significant risk of perforation. Intrasphincteric injection of botulinum toxin A produces satisfactory initial results but the effects wear off within months. Further injections can be given. It is safer and simpler than dilatation, so may be valuable in patients at risk of death if a perforation occurs. Neither pneumatic dilatation nor botulinum toxin works as well in younger patients.

Surgical division of the LOS, Heller’s operation, usually performed laparoscopically is the surgical treatment of choice. This can now be performed endoscopically.

Reflux oesophagitis complicates all procedures and the aperistalsis of the oesophagus remains.

Systemic sclerosis

The oesophagus is involved in almost all patients with this disease. Diminished peristalsis and oesophageal clearance, detected manometrically (Fig. 6.7) or by barium swallow, is due to replacement of the smooth muscle by fibrous tissue. LOS pressure is decreased, allowing reflux with consequent mucosal damage. Strictures may develop. Initially there are no symptoms, but dysphagia and heartburn occur as the oesophagus becomes more severely involved. Similar motility abnormalities may be found in other autoimmune rheumatic disorders, particularly if Raynaud’s phenomenon is present. Treatment is as for reflux (see p. 240) and benign stricture.

Other oesophageal disorders

Rings and webs

An oesophageal web is a thin, membranous tissue flap covered with squamous epithelium. Most acquired webs are located anteriorly in the postcricoid region of the cervical oesophagus and are well seen on barium swallow. They may produce dysphagia. In the Plummer–Vinson syndrome (or Paterson–Brown–Kelly syndrome), a web is associated with chronic iron deficiency anaemia, glossitis and angular stomatitis. This rare syndrome affects mainly women and its aetiology is not understood. The web may be difficult to see at endoscopy and may be ruptured unintentionally by the passage of the endoscope. Dilatation of the web is rarely necessary. Iron is given for the iron deficiency.

Benign oesophageal stricture

Peptic stricture secondary to reflux is the most common cause of benign strictures (for treatment, see p. 241). They also occur after the ingestion of corrosives, after radiotherapy, after sclerosis of varices, and following prolonged nasogastric intubation. Dysphagia is usually treated by endoscopic dilatation. Surgery is sometimes required.

Eosinophilic oesophagitis

Eosinophils can be seen in the oesophageal mucosa (which is usually devoid of eosinophils microscopically) due to a variety of causes such as eosinophilic (or allergic) oesophagitis and GORD.

Eosinophilic oesophagitis is being increasingly recognized but its pathogenesis is unknown. There may be a personal or family history of allergic disorders such as food allergy.

Patients present with a long history of dysphagia, food impaction, ‘heartburn’ and oesophageal pain. Usually the patient is male, white, and with an average age at diagnosis of 35, but it also occurs in children.

Typical endoscopic abnormalities include mucosal furrowing, loss of vascular pattern due to a thickened mucosa, plaques of eosinophilic surface exudate and prominent circular folds, but the oesophagus may appear macroscopically normal. Reflux oesophagitis and Schatzki’s rings may co-exist. Endoscopic forceps biopsies (× 6) should be taken from upper, mid and lower oesophagus for histology with eosinophil counts.

The eosinophilic infiltration of the oesophagus due to reflux disease can be excluded by rebiopsy after a 6-week course of full-dose PPI, when the eosinophil count will have fallen to below 15 per high power field

Treatment is topical, swallowing inhaled steroid preparations such as fluticasone, budesonide syrup, systemic steroids or elimination diets (more beneficial in children). Mepolizumab, a humanized monoclonal antibody against IL-5, has shown some benefit in small trials. Dilatation is sometimes necessary, with a risk of perforation of 2%.

Oesophageal tumours

Cancer of the oesophagus

This is the sixth most common cancer worldwide. Squamous cancers occurring in the middle third account for 40% of tumours, and in the upper third, 15%. Adenocarcinomas occur in the lower third of the oesophagus and at the cardia and represent approximately 45% of tumours. Primary small cell cancer is extremely rare.

Epidemiology and aetiological factors

Squamous cell carcinoma (SCC)

The geographic variation in incidence is greater than for any other carcinoma – often in regions very close to one another. It is common in Ethiopia, China, South and east Africa and in the Caspian regions of Iran. By contrast, north, middle and west Africa have low rates.

In the UK, the incidence is 5–10 per 100 000 and represents 2.2% of all malignant disease. The incidence of SCC is decreasing, in contrast to adenocarcinoma. SCC of the oesophagus is more common in men (2 : 1). Risk factors are shown in Table 6.5.

Table 6.5 Risk factors for cancer of the oesophagus

Squamous cell carcinoma Adenocarcinoma

Tobacco smoking

Longstanding, heartburn

High alcohol intake

Barrett’s oesophagus

Plummer–Vinson syndrome

Tobacco smoking

Achalasia

Obesity

Corrosive stricturesCoeliac diseaseBreast cancer treated with radiotherapy

Breast cancer treated with radiotherapy

Older age

 

Tylosisa

 

a Tylosis is a rare autosomal dominant condition with hyperkeratosis of the palms and soles.

High levels of alcohol consumption increase the risk of squamous cell cancer of the oesophagus, while tobacco use is associated with an increased incidence of both squamous cell and adenocarcinomas of the oesophagus. Smoking, obesity and low fruit and vegetable consumption are implicated in approximately 9 in 10 squamous cell cancers of the oesophagus.

Diets rich in fibre, carotenoids, folate, vitamin C and non-starchy vegetables probably decrease the risk of oesophageal cancer whereas diets high in saturated fat and cholesterol and refined cereals have been associated with an increased risk. Red and processed meat intake has been associated with an increased risk of both oesophageal SCC and adenocarcinoma. Conversely, fish and white meat consumption have been inversely associated with risk of oesophageal SCC in case–control studies from Italy, Switzerland and Uruguay.

Adenocarcinoma

These tumours primarily arise in columnar-lined epithelium in the lower oesophagus (see also Barrett’s oesophagus, p. 241). The incidence of this tumour is increasing in western industrialized countries). A study of the cancer registry in the USA estimated that incidence in white males rose four-fold from 1979 to 2004. Extension of an adenocarcinoma of the gastric cardia into the oesophagus can present with the same symptoms. Previous reflux symptoms increase the risk up to eight-fold and the risk is proportional to their severity.

Investigation

Treatment

Although oesophageal SCC and adenocarcinomas are undoubtedly two different disease processes with independent tumour biology, the majority of trial data does not discriminate the two. Before 2010, they shared identical TNM staging system. How histology should influence treatment is therefore unclear and varies around the globe.

Treatment is dependent on the age and performance status of the patient and the stage of the disease. Five-year survival with stage 1 is 80% (T1/T2, N0, M0), stage 2 is 30%, stage 3 is 18% and stage 4 is 4%. Some 70% of patients present with stage 3 or greater disease, so that overall survival is 27% at 1 year and around 10% at 5 years. Management should be undertaken by multidisciplinary teams.

image Surgery provides the best chance of a cure but should only be used only when imaging (see above) has shown that the tumour has not infiltrated outside the oesophageal wall. Less than 40% of patients will have potentially resectable disease at the time of presentation. Patients must be carefully evaluated preoperatively, particularly with regard to performance status (see p. 253), and surgery undertaken in designated units. Poor outcome data from surgery alone has challenged its role as monotherapy and it is more often used in conjunction with neo-adjuvant (preoperative) and adjuvant (postoperative) treatment.

image Chemoradiation. Preoperative (‘neo-adjuvant’) chemoradiation therapy may benefit patients with stage 2b and 3 disease. Prolongation of survival has been shown in some studies. In the USA neo-adjuvant chemoradiotherapy is preferred to the neo-adjuvant chemotherapy that is typically used in the UK.

image Palliative therapy is often the only realistic possibility. Dilatation is only of short-term benefit and the perforation risk is higher than for benign strictures. Combination of endoscopic dilatation with laser or brachytherapy (see p. 447) prolongs luminal patency and gives as good if not better functional results than stenting. Insertion of an expanding metal stent allows liquids and soft foods to be eaten.

image Photodynamic therapy (PDT) can be useful in more superficial cancers.

image Chemoradiation alone is sometimes given, but evidence of benefit is poor except in early stage SCC.

image Nutritional support, as well as support for the patient and their family, is vital in this distressing condition.

Other oesophageal tumours

Most other tumours are rare. Gastrointestinal stromal tumours (see p. 253) and leiomyomas (both submucosal tumours) are found usually by chance; 10% cause dysphagia or bleeding. Surgical removal is performed for symptomatic lesions or those over 3 cm, which are more likely to harbour malignancy. Small benign tumours are relatively common and often do not require treatment.

Kaposi’s sarcoma is found in the oesophagus as well as the mouth (see p. 193) and hypopharynx in patients with AIDS.

The stomach and duodenum

Structure

The stomach occupies a small area immediately distal to the oesophagus (the cardia), the upper region (the fundus, under the left diaphragm), the mid-region or body and the antrum, which extends to the pylorus (Fig. 6.8). It serves as a reservoir where food can be retained and broken up before being actively expelled in to the proximal small intestine.

The smooth muscle of the wall of the stomach has three layers: outer longitudinal, inner circular and innermost oblique layers. There are two sphincters, the gastro-oesophageal sphincter and the pyloric sphincter. The latter is largely made up of a thickening of the circular muscle layer and controls the exit of gastric contents into the duodenum.

The duodenum has outer longitudinal and inner smooth muscle layers. It is C-shaped and the pancreas sits in the concavity. It terminates at the duodenojejunal flexure where it joins the jejunum.

image The mucosal lining of the stomach can stretch in size with feeding. The greater curvature of the undistended stomach has thick folds or rugae. The mucosa of the upper two-thirds of the stomach contains parietal cells that secrete hydrochloric acid, and chief cells that secrete pepsinogen (which initiates proteolysis). There is often a colour change at the junction between the body and the antrum of the stomach that can be seen macroscopically, and confirmed by measuring surface pH.

image The antral mucosa secretes bicarbonate and contains mucus-secreting cells and G cells, which secrete gastrin, stimulating acid production. There are two major forms of gastrin, G17 and G34, depending on the number of amino-acid residues. G17 is the major form found in the antrum. Somatostatin, a suppressant of acid secretion, is also produced by specialized antral cells (D cells).

image Mucus-secreting cells are present throughout the stomach and secrete mucus and bicarbonate. The mucus is made of glycoproteins called mucins.

image The mucosal barrier, made up of the plasma membranes of mucosal cells and the mucus layer, protects the gastric epithelium from damage by acid and, for example, alcohol, aspirin, NSAIDs and bile salts. Prostaglandins stimulate secretion of mucus, and their synthesis is inhibited by aspirin and NSAIDs, which inhibit cyclo-oxygenase (see Fig. 15.30).

image The duodenal mucosa has villi like the rest of the small bowel, and also contains Brunner’s glands that secrete alkaline mucus. This, along with the pancreatic and biliary secretions, helps to neutralize the acid secretion from the stomach when it reaches the duodenum.

Gastritis and gastropathy

Helicobacter pylori infection

H. pylori is a slow-growing spiral Gram-negative flagellate urease-producing bacterium (Fig. 6.16) which plays a major role in gastritis and peptic ulcer disease. It colonizes the mucous layer in the gastric antrum, but is also found in the duodenum in areas of gastric metaplasia. H. pylori is found in greatest numbers under the mucous layer in gastric pits, where it adheres specifically to gastric epithelial cells. It is protected from gastric acid by the juxtamucosal mucous layer which traps bicarbonate secreted by antral cells, and ammonia produced by bacterial urease.

Figure 6.16 Helicobacter pylori. (a) Organisms (arrowed) are shown on the gastric mucosa (cresyl fast violet (modified Giemsa) stain).

(Courtesy of Dr Alan Phillips, Department of Paediatric Gastroenterology, Royal Free Hospital.)

image

Pathogenesis

The pathogenetic mechanisms are not fully understood, with the majority of the colonized population remaining asymptomatic throughout their life. H. pylori is highly adapted to the stomach environment, exclusively colonizing gastric epithelium and inhabiting the mucous layer, or just beneath. It adheres by a number of adhesion molecules including BabA, which binds to the Lewis antigen expressed on the surface of gastric mucosal cells and causes gastritis in all infected subjects. Damage to the gastric epithelial cell is caused by the release of enzymes and the induction of apoptosis through binding to class II MHC molecules. The production of urease enables the conversion of urea to ammonium and chloride, which are directly cytotoxic. Ulcers are commonest when the infecting strain expresses CagA (cytotoxic-associated protein) and VacA (vacuolating toxin) genes secondary to a more pronounced inflammatory and immune response. Expression of CagA and VacA is associated with greater induction of IL-8, a potent mediator of gastric inflammation. Genetic variations in the host are also thought to be involved; for example, polymorphisms leading to increased levels of IL-1β are associated with atrophic gastritis and cancer.

Results of infection

Antral gastritis is the usual effect of H. pylori infection. It is usually asymptomatic, although patients without ulcers do sometimes experience relief of dyspeptic symptoms after Helicobacter eradication. Chronic antral gastritis causes hypergastrinaemia due to gastrin release from antral G cells. The subsequent increase in acid output is usually asymptomatic, but can lead to duodenal ulceration

Duodenal ulcer (DU) (see Fig. 6.18a). The prevalence of H. pylori infection in patients with duodenal ulceration is falling and in the developed world is now between 50% and 75%, whereas duodenal ulceration was once rare in the absence of H. pylori infection. This has been attributed to a decrease in prevalence of the bacteria and an increase in NSAID use. Eradication of the infection improves ulcer healing and decreases the incidence of recurrence.

The precise mechanism of duodenal ulceration is unclear, as only 15% of patients infected with H. pylori (50–60% of the adult population worldwide) develop duodenal ulcers. Factors that have been implicated include: increased gastrin secretion, smoking, bacterial virulence and genetic susceptibility.

Gastric ulcer (GU) (see Fig. 6.18b). Gastric ulcers are associated with a gastritis affecting the body as well as the antrum of the stomach (pangastritis) causing parietal cell loss and reduced acid production. The ulcers are thought to occur because of reduction of gastric mucosal resistance due to cytokine production by the infection or perhaps to alterations in gastric mucus.

Peptic ulcer disease

A peptic ulcer consists of a break in the superficial epithelial cells penetrating down to the muscularis mucosa of either the stomach or the duodenum; there is a fibrous base and an increase in inflammatory cells. Erosions, by contrast, are superficial breaks in the mucosa alone. Most DUs are found in the duodenal cap; the surrounding mucosa appears inflamed, haemorrhagic or friable (duodenitis). GUs are most commonly seen on the lesser curve near the incisura, but can be found in any part of the stomach.

Diagnosis of Helicobacter pylori infection

Diagnosis of H. pylori is necessary if the clinician plans to treat a positive result. This is usually in the context of active peptic ulcer disease, previous peptic ulcer disease or MALT lymphoma, or to ‘test and treat’ patients with dyspepsia under the age of 55 with no alarm symptoms (i.e. weight loss, anaemia, dysphagia, vomiting, or family history of gastrointestinal cancer).

Non-invasive methods

image Serological tests detect IgG antibodies and are reasonably sensitive (90%) and specific (83%). They have been used in diagnosis and in epidemiological studies. IgG titres may take up to 1 year to fall by 50% after eradication therapy and therefore are not useful for confirming eradication or the presence of a current infection. Antibodies can also be found in the saliva, but tests are not as sensitive or specific as serology.

image 13C-Urea breath test (Fig. 6.17). This is a quick and reliable test for H. pylori and can be used as a screening test. The measurement of 13CO2 in the breath after ingestion of 13C urea requires a mass spectrometer. The test is sensitive (90%) and specific (96%), but the sensitivity can be improved by insuring the patient has not taken antibiotics in the 4 weeks prior and proton pump inhibitors in the 2 weeks before the test.

image Stool antigen test. This is beginning to supersede breath testing as the method with which to determine H. pylori status. A specific immunoassay using monoclonal antibodies for the qualitative detection of H. pylori antigen is now widely available. The overall sensitivity is 97.6% with a specificity of 96%. It is useful in the diagnosis of H. pylori infection and for monitoring efficacy of eradication therapy. Patients should be off PPIs for 2 weeks but can continue with H2 blockers. Newer stool antigen tests are being developed that can be performed in the clinic setting, although at present the sensitivity and specificity are not as good as those performed in the laboratory.

Eradication therapy

Current recommendations are that all patients with duodenal and gastric ulcers should have H. pylori eradication therapy if the bacteria is present. Many patients have incidental H. pylori infection with no gastric or duodenal ulcer. Whether all such patients should have eradication therapy is controversial (see Functional dyspepsia, p. 296).

The increase in the prevalence of GORD and adenocarcinoma of the lower oesophagus in the last few years is currently unexplained, but has been postulated to be linked to eradication of H. pylori. This seems unlikely but is not disproven.

Depending on local antibacterial resistance patterns standard eradication therapies in the developed world are successful in approximately 90% of patients.

Reinfection is very uncommon (1%) in developed countries. In developing countries reinfection is more common, compliance with treatment may be poor and metronidazole resistance is high (>50%) (as it is frequently used for parasitic infections), so failure of eradication is common.

There are many regimens for eradication, but all must take into account that:

Metronidazole, clarithromycin, amoxicillin, tetracycline and bismuth are the most widely used agents. Resistance to amoxicillin (1–2%) and tetracycline (<1%) is low except in countries where they are available without prescription where resistance may exceed 50%. Quinolones such as ciprofloxacin, furazolidone and rifabutin are also used when standard regimens have failed (‘rescue therapy’). None of these drugs is effective alone; eradication regimens therefore usually comprise two antibiotics given with powerful acid suppression in the form of a PPI. Recent evidence has advocated bismuth-containing quadruple therapy as first-line because of increasing clarithromycin resistance.

Example regimens are

These should be given for 7 or 14 days. Two-week treatments increase the eradication rates but increased side-effects may reduce compliance. Bismuth chelate is not usually given in initial regimens because of the more complex dosing regimen and side-effects. However, a single capsule is now available.

In eradication failures, bismuth chelate (120 mg 4× daily); metronidazole (400 mg 3× daily); tetracycline (500 mg 4× daily) and a PPI (20–40 mg 2× daily) for 14 days, is used. Sequential courses of therapy are being used in areas where resistance is high. With the increase in clarithromycin resistance, many are using this quadruple therapy for initial treatment.

Prolonged therapy with a PPI after a course of PPI-based 7-day triple therapy is not necessary for ulcer healing in most H. pylori-infected patients. The effectiveness of treatment for uncomplicated duodenal ulcer should be assessed symptomatically. If symptoms persist, breath or stool testing should be performed to check eradication.

Patients with a risk of bleeding or those with complications, i.e. haemorrhage or perforation, should always have a 13C urea breath test or stool test for H. pylori 6 weeks after the end of treatment to be sure eradication is successful. Long-term PPIs may be necessary if a rebleed would be likely to be fatal.

Complications of peptic ulcer

Surgical treatment and its long-term consequences

Once the mainstay of treatment, surgery is now used in peptic ulcer disease only for complications including:

No other procedure, such as gastrectomy or vagotomy, is required.

In the past, two types of operation were performed:

Long-term complications of surgery which are still seen occasionally include:

NSAIDs, Helicobacter and ulcers

Aspirin and other NSAIDs deplete mucosal prostaglandins by inhibiting the cyclo-oxygenase (COX) pathway, which leads to mucosal damage. Cyclo-oxygenase occurs in two main forms: COX-1, the constitutive enzyme, and COX-2, inducible by cytokine stimulation in areas of inflammation. COX-2 specific inhibitors have less effect on the COX-1 enzyme in the gastric mucosa, but still produce gastric mucosal damage but less than with other conventional NSAIDs. Their use is limited by concern regarding cardiovascular side-effects.

Some 50% of patients taking regular NSAIDs will develop gastric mucosal damage and approximately 30% will have ulcers on endoscopy. Only a small proportion of patients have symptoms (about 5%) and only 1–2% have a major problem, i.e. GI bleed. Because of the large number of patients on NSAIDs including low-dose aspirin for vascular prophylaxis, this is a significant problem, particularly in the elderly.

H. pylori and NSAIDs are independent and synergistic risk factors for the development of ulcers. In a meta-analysis, the odds ratio (OR) for the incidence of peptic ulcer was 61.1 in patients infected with H. pylori and also taking NSAIDs, compared with uninfected controls not taking NSAIDs.

Gastric tumours

Adenocarcinoma

Gastric cancer is currently the fourth most common cancer found worldwide and the second leading cause of cancer-related mortality. The incidence increases with age (peak incidence 50–70 years), and it is rare under the age of 30 years. The highest incidences of the disease are found in Eastern Asia, Eastern Europe and South America. The incidence in men is twice that in women and varies throughout the world, being high in Japan (M: 53/100 000, F: 21.3/100 000) and Chile and relatively low in the USA (M: 7/100 000, F: 2.9/100 000). In the UK carcinoma of the stomach (see Fig. 6.1) is the eighth most common cancer (M: 16/100 000, F 9/100 000). Although the overall worldwide incidence of gastric carcinoma is falling, even in Japan, probably due to reductions in incidence of Helicobacter and before this, improvements in food storage, proximal gastric cancers are increasing in the West and have very similar demographic and pathological features as Barrett’s associated oesophageal adenocarcinoma.

Epidemiology and pathogenesis

image There is a strong link between H. pylori infection and distal gastric cancer. H. pylori is recognized by the International Agency for Research in Cancer (IARC) as a Group 1 (definite) gastric carcinogen. H. pylori infection causes chronic gastritis which eventually leads to atrophic gastritis and premalignant intestinal metaplasia (Fig. 6.19). Much of the earlier epidemiological data (i.e. the increase of cancer in lower socioeconomic groups) can be explained by the intrafamilial spread of H. pylori. Epstein–Barr virus is detected in 2–16% of gastric cancers worldwide, but its role in aetiology is not well understood.

image Dietary factors may also be involved (as both initiators and promoters) and have separate roles in carcinogenesis. Diets high in salt probably increase the risk. Dietary nitrates can be converted into nitrosamines by bacteria at neutral pH, and nitrosamines are known to be carcinogenic in animals but the evidence in human carcinogenesis is limited. Nitrosamines are also present in the stomach of patients with achlorhydria, who have an increased cancer risk.

image Smoking tobacco is associated with an increased incidence of stomach cancer.

image Genetic abnormality. The commonest is a loss of heterozygosity (LOH) of tumour suppressor genes such as p53 (in 50% of cancers as well as in pre-cancerous states) and the APC gene (in over one-third of gastric cancers). These abnormalities are similar to those found in colorectal cancers. Some rare families with diffuse gastric cancer have been shown to have mutations in the E-cadherin gene (CDH-1). There is a higher incidence of gastric cancer in blood group A patients.

image First-degree relatives of patients with gastric cancer have two- to three-fold increased relative risk of developing the disease, but this may be environmental rather than inherited.

image Pernicious anaemia carries a small increased risk of gastric carcinoma due to the accompanying atrophic gastritis.

image There is an increased risk of gastric cancer after a partial gastrectomy (postoperative stomach) whether performed for a gastric or a duodenal ulcer, probably due to untreated H. pylori infection.

Clinical features

Diagnosis

image Gastroscopy (Fig. 6.20). Gastroscopy is performed so that biopsies can be taken for histological assessment. Positive biopsies can be obtained in almost all cases of obvious carcinoma, but a negative biopsy does not necessarily rule out the diagnosis. For this reason, 8–10 biopsies should be taken from suspicious lesions. Superficial brushings for cytology further improve the diagnostic rate.

Staging

The TNM classification is used. The tumour grade (T) indicates depth of tumour invasion, N denotes the presence or absence of lymph nodes, M indicates presence or absence of metastases. TNM classification is then combined into stage categories 0–4. At presentation, two-thirds of patients are at stage 3 or 4, i.e. advanced disease (Table 6.6). The histological grade of the tumour also determines survival.

Table 6.6 Gastric cancer – staging and 5-year survival rates

Stage TNM stage 5-year survival (%)

1

T1N0M0, T1N1M0 or T2N0M0

88

2

T1N2M0, T2N1M0 or T3N0M0

65

3a

T2N2M0, T3N1M0 or T4N0M0

35

3b

T3N2M0

35

4

T4N1–3M0, TxN3M0 or TxNxM1a

5

T, tumour; N, nodes; M, metastases. aTx indicates any T stage; Nx, any N stage.

Treatment

As with all cancers, treatment is discussed with a multidisciplinary team. Early non-ulcerated mucosal lesions can be removed endoscopically by either endoscopic mucosal resection or endoscopic submucosal desection.

Surgery remains the most effective form of treatment if the patient is an operative candidate. Careful selection has reduced the numbers undergoing surgery and has improved the overall surgical 5-year survival rates to around 30%. Five-year survival rates in ‘curative’ operations are as high as 50%. Surgery and combined chemoradiotherapy and treatment of advanced disease is described on page 477. The multinational MAGIC trial demonstrated the benefits of perioperative chemotherapy with epirubicin, cisplatin and infusional 5-fluorouracil (ECF) (see Table 9.10), where 5-year survival in operable gastric and lower oesophageal adenocarcinomas increased from 23% to 36%. An alternative regimen is oral epirubicin, oxaliplatin and capecitabine. Despite the improved results, the overall survival rate for a patient with gastric carcinoma has not dramatically improved, with a maximum 10% 5-year survival rate overall. Palliative care with relief of pain and counselling are usually required.

Acute and chronic gastrointestinal bleeding

This section should be read in conjunction with the descriptions of the specific conditions mentioned.

Acute upper gastrointestinal bleeding

The cardinal features are haematemesis (the vomiting of blood) and melaena (the passage of black tarry stools; the black colour due to blood altered by passage through the gut). Melaena can occur with bleeding from any lesion proximal to the right colon. Following a bleed from the upper GI tract, unaltered blood can appear per rectum, but the bleeding must be massive and is almost always accompanied by shock. The passage of dark blood and clots without shock is always due to lower GI bleeding.

Clinical approach to the patient

All cases with a recent (i.e. within 48 hours) significant GI bleed should be seen in hospital. In many, no immediate treatment is required as there has been only a small amount of blood loss. Approximately 85% of patients stop bleeding spontaneously within 48 hours.

Scoring systems have been developed to assess the risk of rebleeding or death.

Table 6.7 shows the Rockall score, which is based on clinical and endoscopy findings. The Blatchford score uses the level of plasma urea, haemoglobin and clinical markers but not endoscopic findings to determine the need for intervention such as blood transfusion or endoscopy in GI bleeding.

The following factors affect the risk of rebleeding and death:

Bleeding associated with liver disease is often severe and recurrent if it is from varices. Liver failure can develop.

Immediate management

This is shown in Emergency Box 6.1. In addition, stop NSAIDs, aspirin, clopidogrel and warfarin if patients are taking them. Stopping antiplatelets can be dangerous and produce thrombosis: discuss urgently with a cardiologist.

Many hospitals have multidisciplinary specialist teams with agreed protocols and these should be followed carefully. Patients should be managed in high-dependency beds. Oxygen should be given by facemask and the patient should be kept nil by mouth until endoscopy has been performed.

Patients with large bleeds and clinical signs of shock require urgent resuscitation. Details of the management of shock are given in Figure 16.25.

Endoscopy

Endoscopy will usually make a diagnosis, risk stratify and enable therapy to be performed if needed. Endoscopy should be performed as soon as possible after the patient has been resuscitated. Patients with Rockall scores of 0 or 1 pre-endoscopy may be candidates for immediate (see over) discharge and outpatient endoscopy the following day, depending on local policy.

Endoscopy can detect the cause of the haemorrhage in 80% or more of cases. In patients with a peptic ulcer, if the stigmata of a recent bleed are seen (i.e. a spurting vessel, active oozing, fresh or organized blood clot or black spots) the patient is more likely to rebleed. Calculation of the post-endoscopy Rockall score gives an indication of the risk of rebleeding and death.

Specific conditions

Oesophageal varices. These are discussed on page 924.

Mallory–Weiss tear. This is a linear mucosal tear occurring at the oesophagogastric junction and produced by a sudden increase in intra-abdominal pressure. It often occurs after a bout of coughing or retching and is classically seen after alcoholic ‘dry heaves’. There may, however, be no antecedent history of retching. Most bleeds are minor and discharge is usual within 24 hours. The haemorrhage may be large but most patients stop spontaneously. Early endoscopy confirms diagnosis and allows therapy if necessary. Surgery with oversewing of the tear is rarely needed.

Chronic peptic ulcer. Eradication of H. pylori is started as soon as possible (see p. 249). A PPI is continued for 4 weeks to ensure ulcer healing. Eradication of H. pylori should always be checked in a patient who has bled and long-term acid suppression given if HP eradication is not achieved. If bleeding is not controlled the patient should either undergo angiography and embolization or be referred directly for surgery.

Gastric carcinoma. Most of these patients do not have large bleeds but surgery is occasionally necessary for uncontrolled or repeat bleeding. Usually, surgery can be delayed until the patient has been fully evaluated (see p. 253). Oozing from gastric cancer is very difficult to control endoscopically. Radiotherapy can occasionally be successful.

Bleeding after percutaneous coronary intervention (PCI). In the era of ever more aggressive percutaneous coronary intervention the list of anti thrombotic medication grows longer: glycoprotein IIb/IIIa inhibitors, unfractionated heparin, low molecular weight heparin, fundoparinux, platelet inhibitors (e.g. clopidogrel, prasugrel). These, in addition to the oral anticoagulants that this group of patients are often taking, give rise to a GI bleeding rate of approximately 2% of patients undergoing PCI (who are on antiplatelet therapy, e.g. clopidogrel), and has a high mortality of 5–10%. It has become increasingly evident in this patient group that gastroscopy should be performed on an urgent basis and not deferred for days or weeks. A bolus of i.v. PPI is administered followed by an infusion; platelet infusion is given to counter the effect of clopidogrel. Management is difficult as cessation of antiplatelet therapy has a high risk of acute stent thrombosis and also an associated high mortality. Using a risk assessment score (e.g. Rockall, Table 6.7), a reasonable approach is to stop all antiplatelet therapy in high-risk patients but continue in low-risk ones. Co-prescribed proton pump inhibition does not decrease the antiplatelet effect of clopidogrel as was first thought. These patients should be under the combined care of a cardiologist and a gastroenterologist.

Chronic gastrointestinal bleeding

Patients with chronic bleeding usually present with iron-deficiency anaemia (see Ch. 8).

Chronic blood loss producing iron deficiency anaemia in all men, and all women after the menopause, is always due to bleeding from the GI tract. The primary concern is to exclude cancer, particularly of the stomach or right colon, and coeliac disease. Occult blood tests are unhelpful (Box 6.5). Iron deficiency anaemia can be due to poor iron intake (rare) or absorption as well as chronic blood loss.

Diagnosis

Chronic blood loss can occur with any lesion of the GI tract that produces acute bleeding (Figs 6.21, 6.22). However, oesophageal varices usually bleed obviously and rarely present as chronic blood loss. Although uncommon in developed countries, hookworm is the most common worldwide cause of chronic GI blood loss.

History and examination may indicate the most likely site of the bleeding, but if no clue is available it is usual to investigate both the upper and lower GI tract endoscopically at the same session (‘top and tail’):

If gastroscopy, colonoscopy and duodenal biopsy have not revealed the cause, investigation of the small bowel is necessary. Capsule endoscopy is the diagnostic investigation of choice, but currently has no therapeutic ability. Positive diagnostic yield varies from 60% to 85% depending on series. Bleeding lesions can be identified and later treated with balloon-assisted enteroscopy.

Occasionally, intravenous technetium-labelled colloid may be used to demonstrate a potential bleeding site in a Meckel’s diverticulum.

Treatment

The cause of the bleeding should be treated, if found. Oral iron is given to treat anaemia (see p. 380), although intravenous infusions are occasionally required. Some patients will require maintenance with regular transfusion as a last resort.