Constipation (Case 23)

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Chapter 30
Constipation (Case 23)

Christopher P. Farrell DO and Gary Newman MD

Case: A 67-year-old woman presents to the ED complaining of abdominal discomfort, decreased frequency of her bowel movements, and mild abdominal distension. She is clearly distressed in the ED, unable to find a comfortable position on the stretcher, and wincing with abdominal pain.

Differential Diagnosis

Irritable bowel syndrome (IBS)	Impaction
Colon cancer	Medication-related
Volvulus	Acute colonic pseudo-obstruction (Ogilvie syndrome)

Speaking Intelligently

When asked to see a patient for constipation, we first want to find out the patient’s definition of constipation. Has she not been able to move her bowels in days or is it just not as frequently or as comfortable as she would like? Most cases of constipation aren’t critical; however, a bowel obstruction or volvulus requires more urgent care. If she has not been able to move her bowels or pass any gas for days, she may need more immediate treatment. A thorough history is important, concentrating on alarm symptoms such as unintentional weight loss, rectal bleeding, or a recent or sudden change in bowel habits. Any surgical history should be reviewed, along with the patient’s medications, followed by a dedicated abdominal and rectal exam.

PATIENT CARE

Tests for Consideration

• Basic metabolic panel (BMP): Check for electrolyte abnormalities that can cause an ileus.	$12
• CBC: Look for iron deficiency anemia, possibly unmasking an undiagnosed colon cancer.	$11
• Thyroid function studies: Look for evidence of hypothyroidism as an underlying cause for constipation.	$24
• Flexible sigmoidoscopy or colonoscopy: Rule out masses or mechanical reasons for obstruction in the colon or rectum.	$436, $655

IMAGING CONSIDERATIONS

→ Abdominal radiograph or obstruction series: Usually the first examination to be performed, this may demonstrate dilated loops of bowel, excessive stool throughout the colon, or fecal impaction. A sigmoid volvulus will be noted as a greatly dilated sigmoid colon and a “coffee bean” sign or “bird’s beak” sign.	$45, $75
→ CT scan of abdomen and pelvis: Illustrates cross-sectional images of the abdomen and pelvis allowing for radiographic examination of the bowel wall and its contents. Thickening, narrowing, and masses will be noted. Oral contrast allows the visualization of the inside of the colon, while intravenous contrast allows determination of abnormalities in the bowel wall and surrounding vasculature.	$334
→ Barium enema: Although this test is no longer performed regularly, it still does hold some value. The study can display inflammatory changes of the rectum or colon, can detect masses, and is the treatment for intussusception in children.	$142

Clinical Entities

Medical Knowledge

Irritable Bowel Syndrome
Pφ	IBS is a very common disorder characterized by abdominal pain, bloating, and altered bowel habits. The condition can affect both sexes at any age but is prominent in young females. Patients regularly experience abdominal cramping that is relieved with a bowel movement. The bowel habits can be either constipation-predominant or diarrhea-predominant in nature. Constipation-predominant patients usually experience chronic constipation with intermittent diarrhea or regular bowel movements. The pathophysiology of IBS remains unknown; however, hereditary and environmental factors probably play a role. Psychosocial dysfunction also contributes to IBS and its fluctuating symptoms.
TP	Crampy abdominal pain, incomplete evacuation of bowels, bloating, gas (flatulence or belching), hard or lumpy stools, relief of abdominal discomfort with defecation.
Dx	The main diagnostic tool is the Rome III diagnostic criteria. This includes recurrent abdominal pain or discomfort at least 3 days a month for the last 3 months associated with two of the following: improvement with defecation, onset associated with a change in frequency of stool, or onset associated with a change in form (appearance) of stool.
Tx	Initially, constipation-predominant patients can be treated with fiber supplementation and psychosocial therapies, if emotional stress is a contributing factor. A bowel regimen in the form of a laxative, suppository, or enema may be needed if symptoms persist. Finally, specific medications that activate chloride channels or stimulate the release of serotonin can be used in refractory cases. See Cecil Essentials 34.