Introduction

Halligan et al. (2003) and Halligan (2004) have suggested that ‘a barium enema list is not the attractive proposition it once was’ and that ‘radiologists, both trainees and consultants, are less inclined to take an interest’ in barium enema; in addition, the lack of interest is compounded by the perception that the examination is ‘old fashioned and behind the cutting edge of imaging’. The belief that the sensitivity of the double contrast barium enema (DCBE) for colorectal cancer (CRC) is poor at only about 85% adds to the lukewarm view of the examination. Indeed, Shorvon (2003) implied that there is no room for improving the DCBE and that it is ‘on a developmental plateau’.

It has been suggested by Glick (1997) that there has been a bias against the DCBE associated with a number of studies in which 75–95% of missed cancers were perceptive errors rather than technical error. This finding would suggest that many of the possible shortcomings of the DCBE examination could be overcome by double reading.

However, it is possible to achieve a very high sensitivity if appropriate attention is given to technique. It may be the case that the image sequence of the DCBE has been optimized, but fluoroscopy equipment continues to improve and is now producing higher quality images at a fraction of the radiation dose required just a few years ago.

In the USA, the DCBE was considered to detect the majority of clinically important lesions and was therefore deemed to be an appropriate method for colorectal cancer screening (Winawer et al., 1997). These considerations were supported by the American College of Gastroenterology, The American Association of Colon and Rectal Surgeons and the American Society of Gastrointestinal Endoscopy. A survey of US radiologists, published in 2002, indicated that 75% believe the DCBE to be a ‘very effective’ colorectal cancer screening procedure and, at that time, Medicare approved DCBE as a CRC screening modality in the USA (Klabunde et al., 2002). Ciatto and Castiglione (2002), in reviewing the use of the DCBE within a screening program, also concluded that DCBE was a useful adjunct to screening colonoscopy.

Complications

Vora and Chapman (2004) reviewed 348 000 barium enemas performed by 59 radiographers; 89 complications were reported (1:3900) including five deaths (a mortality rate of 1:70 000). Culpan and Chapman (2002) reported on 54 complications in a review of 134 700 barium enema examinations performed over a 3-year period by 250 radiographers who had attended the Leeds barium enema training course. The complication rate was 1:2500; three deaths indicated a mortality rate of 1:44 900.

The complication and mortality rates for radiographers are not dissimilar to those reported by Blakeborough et al. (1997a) in reviewing the responses of 756 UK consultant radiologists who had performed 738 216 barium enemas in a 3-year period. A total of 82 complications were reported by 77 radiologists (1:9000) including three deaths (a mortality rate of 1:56 786).

Complications associated with the barium enema include perforations, cardiac events and cerebrovascular accidents. In reviewing rectal perforation after a barium enema, de Freiter et al. (2006) report that the most catastrophic course with a high mortality rate develops from sepsis and peritonitis resulting from intraperitoneal perforation. Also reported as prognostically unfavorable is the venous intravasation of barium.

Comment was also made in this paper regarding the introduction of excessive intracolonic pressures, excessive colonic distension and also concern regarding the use of rectal balloon catheters. These results compare favorably with colonoscopy (de Freiter et al., 2006). Updating the British Society of Gastroenterology guidelines, Teague (2003) refered to previous audits including one by Quine et al. (1995) (in which the 30 day mortality was found to be 1:2000) and he indicated there was no evidence to suggest that mortality rates had improved significantly since the 1990s.

Radiologic technologist and radiographer involvement

Price and Le Masurier (2007) reported results of a study that suggest radiographers are performing barium enema examinations in as many as 80% of district general hospitals (DGHs) in the UK. In the USA, Thompson et al. (2006) reported that, with training, radiologic technologists can perform and interpret fluoroscopic images as effectively as radiologists with a similar sensitivity, specificity, positive and negative predictive value. These results are also supported by Culpan et al. (2002) as well as Booth and Mannion (2005). A review on radiographer DCBE reporting by Law et al. (2008), demonstrating a 98% sensitivity to CRC, also strongly supports the view that examinations by radiographers can have a sensitivity and specificity similar to those carried out by radiologists.

Using smooth muscle relaxants

Hypotonia of the colon and rectum has a number of beneficial effects:

The rectal infusion of agents such as 30 ml of peppermint oil solution has been demonstrated to have an antispasmodic effect (Asao et al., 2003). The most commonly used hypotonic agents are 20 mg in 1 ml hyoscine butylbromide (Buscopan) or 1 mg in 1 ml glucagon (Fink and Aylward, 1995; Goei et al., 1996). The IV injection of Buscopan is likely to have no effect on the diagnostic quality of the examination whether it is given before or after the infusion of barium (Elson et al., 2000).

It is not uncommon practice to avoid giving Buscopan in patients who have glaucoma, however, it has been reported by Fink and Aylward (1995) that the risk only relates to patients with undiagnosed (therefore untreated) angle closure glaucoma. The recommendation is to abandon the question about the presence of glaucoma and advise instead that patients should seek urgent medical advice should eye pain and visual loss develop. However, the authors did recommend caution in the presence of heart disease as this was considered of significant importance (Fink and Aylward, 1995).

The benefits and contraindications of Buscopan (from the Boehringer Ingelheim professional leaflet on 20 mg/1 ml solution ‘Buscopan’) and glucagon (from Novo Nordisk professional leaflet on glucagen 1 mg hypokit) are given in Table 13.1.

Table 13.1 Hyascine butylbromide (Buscopan) versus glucagon (Glucagen)

The double contrast barium enema

Good bowel preparation is an important precursor to a successful DCBE (see Chapter 3). Poor coating or residue can mask or mimic pathology and should be reported as such and an alternative strategy should be suggested (e.g. a limited repeat examination following further bowel preparation, to review those areas not well demonstrated).

Prior to commencement of the examination, talking to the patient can determine the success of the bowel preparation as well as contraindications to the use of hypotonic agents. The practitioner can also identify any limitations of mobility and the nature and degree of any comorbidities, as this might have a bearing on the approach to the examination.

The predominant difference in rectal tube types is related to whether or not they have a balloon cuff. There is limited advantage to having a cuff, as it can assist with contrast retention in a patient with poor sphincter control. However, significant complications can occur, such as perforation, following inadvertent cuff insufflation and barium infusion within the vagina due to incorrect tube placement. Colonic perforation following cuff insufflation in the rectum is associated with high, artificially induced, intraluminal pressure. It has been advised that balloon cuffs should be avoided (Blakeborough et al., 1997b; Chapman and Blakeborough, 1998; Culpan and Chapman, 2002).

The objective standard of all DCBE techniques should be the same:

To provide a collective series of images that demonstrate the whole of the distended colon and rectum in double contrast (with a record of the appendix, terminal ileum or ileocecal valve to confirm arrival at the cecal pole).

If the standard has not been met, the examination, although it may be considered diagnostic is, by definition, technically suboptimal.

The technique described below using ‘C’ arm fluoroscopy is only one of a number of approaches to the DCBE. As long as the objective standards are met and there is consistency of approach, local variances need not be of any consequence.

Air or CO₂ double contrast

Air or carbon dioxide (CO₂) can be given to insufflate the bowel. Although practitioners need to be aware of the risks associated with over distension of the colon, if the bowel is collapsed in any view, consideration should be given to increasing gas input.

There are numerous papers discussing the benefits of air and CO₂. CO₂ dissolves faster and, although the mucosal coating is the same, the discomfort of CO₂ is reported as less. However, air is considered to provide better distension and this might outweigh the advantages in patient acceptability that CO₂ provides. Should colic result from air distension or should the effect of the chosen hypotonic agent wear off, maintaining rectal intubation will allow colonic decompression at any time but, particularly, as a routine at the end of the examination (Scullion et al., 1995, Holemans et al., 1998). One example of a DCBE protocol follows:

• With the patient supine for the injection of an IV smooth muscle relaxant, they are then turned into the left lateral position whereupon a rectal catheter is inserted. Care must be given to guard against vaginal intubation. If intubation is problematic (from, for example, prostatic enlargement), digital examination of the rectum can give guidance in directing the tube. The tube is left in situ for the duration of the examination to allow barium to be drained and replaced with air/CO₂ at any time as well as draining and decompressing the bowel upon completion of the examination.

• The intubated patient is turned prone and the tube taped low to the legs to help with any subsequent barium drainage. A solution such as 567 g EZ EM barium diluted with 550 ml H₂O (103% w/v) is infused with the table tilted a few degrees head down. Intermittent fluoroscopy is of value to confirm flow of barium and that no obstruction is present, in addition a pedunculated polyp, if present, may be seen oscillating within the barium flow. Occasional direct inspection of the tube will help identify if there is any barium seepage.

• Contrast should not be allowed to pass beyond the mid transverse colon. If barium is allowed to reach the right colon, it may well superimpose and denigrate subsequent imaging of the sigmoid colon. The patient is turned from the prone position via their left side to the supine, then to a position turned 45 degrees to the right to coat the rectum and sigmoid. Reversing the patient’s direction the patient is turned prone once more.

• Focusing now only on the colon and rectum, a couple of puffs of air are passed into the rectum to break up the barium column and raise the rectal pressure, and the rectum is then drained of barium.

• Gently puffing air into the rectum, the patient is turned via their left side to the right anterior oblique (RAO) position (Figure 13.1). Depending on the field size capability of the fluoroscopy unit, an RAO of the rectum and sigmoid can be followed by an RAO image of the proximal sigmoid/distal descending colon.

• The patient is now turned via their left side into the prone position and any pooled barium is drained from the rectum and then re-inflated with air. A prone image is taken of the rectum and sigmoid (Figure 13.2) and, if using the ‘C’ arm, a view is also taken of this region with optimum caudal angulation (Figure 13.3) suggestive of Hampton’s view.

• Continuing turning the patient towards the left, the left posterior oblique (LPO) (Figure 13.4) is a mirror image of the RAO and, as such, barium pooling in any loop in one view will be replaced by air in the mirrored image.

• Rotating the patient in the same direction a right lateral image (Figure 13.5) is acquired, making sure the hips are super imposed. This view not only gives a good view of the rectum but is the best view to demonstrate the pre-sacral space. This completes the standard views of the rectosigmoid.

Figure 13.1 Right anterior oblique rectum and sigmoid.

Figure 13.2 Prone rectum and sigmoid.

Figure 13.3 Prone with caudal angulation.

Figure 13.4 Left posterior oblique rectum and sigmoid.

Figure 13.5 Right lateral rectum.

As imaging of the sigmoid colon has been completed, we are not worried at this point that the direction of the patient rotation has been aiding the passage of barium into and over the hepatic flexure. Turning the patient towards the left anterior oblique (LAO), the colon is screened both to make sure there is enough barium to demonstrate the right colon and to identify where barium is pooling in the region of the splenic flexure and descending colon. To remove the pooled barium in the left colon, the table is tilted head up (it is not normally necessary to stand the table erect both from the view point of patient comfort and to reduce the risk of them becoming hypotensive and possibly fainting (Roach et al., 2001)).

• The patient is turned to assist the barium to drain; the direction the patient is turned will depend on the direction the bowel is looping. It no longer matters if drained barium now returns to the sigmoid region. In the left anterior oblique (Figure 13.6) position, insufflating with air as required, an image is taken of the descending colon, splenic flexure and distal transverse colon.

• The hepatic loop may be exaggerated or have a redundant element to it, trapping barium. To advance barium through the hepatic flexure into the ascending colon, it may help to have the table horizontal, turn the patient a few degrees to the left for a moment then onto their back again. Tilt the table head up; this allows the barium to spill into and around the hepatic flexure then down into the ascending colon to the cecum. Imaging of the transverse colon (Figure 13.7) may be optimized at this time.

• With the barium in the cecal pole, coating of the right colon is achieved with the table horizontal and turning the patient onto their left side allowing the barium to coat the medial aspect. Continuing the turn until the patient is prone will enable the barium to coat the anterior aspect of the right colon and hepatic flexure as the barium spills into it. With the patient prone, as well as draining the barium out of the right colon, this position enables air to spill into this region.

• As the patient turns back onto their left side, the right lateral decubitus (Figure 13.8) image can be obtained. It may be necessary to take two images to cover the whole abdomen.

• To obtain views of the hepatic flexure, tilt the table head up and turn the patient so that residual barium falls to the cecal pole then into the RAO for the hepatic flexure (Figure 13.9).

• The cecal pole will often demonstrate a marked posterior cupping and can lie laterally or medially. Emptying barium from the cecum may require turning the patient either to the left or right depending on barium pooling then tilting the table head down. Occasionally, with pronounced cupping, it may be necessary to image the cecum with the patient in the prone position to obtain double contrast imaging of the pole. Except where clinically contraindicated, the cecum should always be palpated and two oblique views imaged (Figures 13.10 and 13.11) with additional views if aspects of the cecum are obscured by the terminal ileum. It must always be borne in mind that, however good the technique, pathology may be subtle (Figures 13.12A, 13.12B).

• Reflux into the terminal ileum not only confirms arrival at the cecal pole but may show itself to be the site of abnormality (Figure 13.13).

• With ‘C’ arm fluoroscopy it may be the case that a whole abdomen might not be possible on a single image, in which case, the lower abdomen can be taken with the table supine, the upper abdomen taken with the table tilted head up to allow air (or CO₂) to migrate to the upper abdomen (see Figure 13.7 and 13.14).

• The last image(s) is the left lateral decubitus (Figures 13.15A, 13.15B). Turning the patient to the right, lay the table horizontal, draining barium from the left colon. Consideration should always be given to replacing expelled gas (Table 13.2).

Figure 13.6 Left anterior oblique distal transverse colon, splenic flexure and descending colon.

Figure 13.7 Transverse colon.

Figure 13.8 Right lateral decubitus.

Figure 13.9 Right anterior oblique hepatic flexure and ascending colon.

Figure 13.10 Cecal pole.

Figure 13.11 Compression view of cecal pole.

Figure 13.12 (A) Apparently normal cecal pole; (B) the same cecum, tumor clearly visible.

Figure 13.13 Normal colon, terminal ileal Crohn’s disease.

Figure 13.14 Supine view lower abdomen.

Figure 13.15 (A) Left lateral decubitus, lower abdomen; (B) left lateral decubitus, upper abdomen.

Table 13.2 Double contrast barium enema positioning and imaging

Activity	Image	Example figure
Patient supine – inject hypotonic agent
Left lateral position – intubate
Turn patient prone
Infuse barium just over the splenic flexure
Turn patient to left then supine
Turn left – prone
Air insufflate, drain barium, air insufflate, turn patient onto left side:
Image 1: Turn towards left then prone	Right anterior oblique	Figure 13.1
Image 2	Prone	Figure 13.2
Image 3	Prone with caudal tube angulation	Figure 13.3
Image 4	Left posterior oblique	Figure 13.4
Image 5 Check barium has reached right colon Drain barium from left side	Left lateral	Figure 13.5
Image 6	Left anterior oblique of descending colon and splenic flexure	Figure 13.6
Barium to cecal pole Image 7 Turn left then prone to coat medial and anterior wall of ascending colon while draining barium from right colon	Supine transverse colon	Figure 13.7
Image 8	Right lateral decubitus	Figure 13.8
Image 9	Right anterior oblique hepatic flexure	Figure 13.9
Image 10	Supine mid ascending (if needed)	Figure 13.10
Image 11	Supine and oblique of cecum with compression	Figure 13.11
Image 12	Supine abdominal overview(s)	Figure 13.12
Image 13	Left lateral decubitus	Figure 13.13

Single contrast enema (SCE)

Historically, an SCE was undertaken on patients with large bowel obstruction that had not perforated to confirm the degree of obstruction and its location. These patients are now better served having a less invasive CT scan (Jacob et al., 2007).

However, the suggestion by Boardman and Nolan (1994) that there are occasions when an SCE examination can be employed is still true today despite the increasing use of CT. The SCE is still of value for patients who are referred for a DCBE but, due to infirmity and immobility, cannot lie prone or turn in a manner required to achieve a full DCBE examination. In these instances, infusing a dilute low density single contrast barium solution can still provide useful information. Following the injection of a hypotonic agent, the patient is turned onto their left side and the barium is infused as far as the hepatic flexure. Patient position and imaging can follow the flow of barium:

At this stage, rather than infusing more barium, draining the rectum and applying a few puffs of air will, in most instances, assist with the filling of the right colon.

Water-soluble contrast enema (Gastrografin enema)

The most common reason for performing a water-soluble contrast enema (WSEN) is as a postoperative check on the integrity and patency of anastomoses following anterior resection (Figure 13.16), total proctocolectomy and ileal pouch-anal anastomosis prior to reversing a defunctioning ileostomy (Dolinsky et al., 2007).

Figure 13.16 Post anterior resection: leak at the stapled anastomotic margin.

Even if defunctioned, a smooth muscle relaxant is of value to relax the bowel. The patient is turned onto their left side for intubation and infusion of contrast. Gastrografin (if used) can be diluted 2:1 water to Gastrografin.

The standard barium enema tips should not be used as they are too rigid and could disrupt the surgical staples (see Figure 13.16). A soft tube such as the 16 Fg Jacques catheter is a safer option, inserting it only as far as it will freely pass. With low anterior resections in particular, over insertion is counter-productive as the contrast is required at the anastomotic margins. Patient positioning is aimed at putting contrast on the respective walls of the bowel (Table 13.3); however, prone imaging is to be avoided if at all possible due to patient discomfort that could be caused from the defunctioning stoma.

Table 13.3 Water-soluble contrast enema image projections to review anastomosis

The WSEN can be of value in determining a mechanical obstruction from an ileus, assessing the level and extent of an obstructive stricture and identifying if a known malignant stricture is suitable for stenting.

Colostomy enema

The difficulty regarding a colostomy enema is the lack of a sphincter to retain the barium. A number of devices and techniques have been designed to allow barium infusion via a colostomy (Kushner et al., 1988; Williams and Scott, 2003).

Examination of the colon may be required following the formation of a colostomy (i.e. post anterior peroneal resection). To retain the barium, a 2 cm slit is made in the colostomy bag on the medial side of the stoma bag and a 10 Fg Law II tube inserted. Depending on the site of the stoma, it is possible to pass the tube over the splenic flexure without too much difficulty (Figures 13.17 and 13.18). Following the injection of a hypotonic agent with the patient lying on their right side, barium can be infused to fill the right colon. Should barium be ejected, it will be contained within the bag which, if needed, can be drained using a suction catheter. Turning the patient supine and then towards the left allows the barium to fill the transverse colon before being aspirated.

Figure 13.17 Colostomy enema: tube passed over hepatic flexure.

Figure 13.18 Colostomy enema: right lateral decubitus.

With the patient on their left side, air can now be infused through the tube. In the left lateral position the air will migrate to, and distend, the right colon (see Figure 13.18). Imaging starts in the right lateral position with the ascending colon. Images can then be taken as required as the patient is turned onto their back (Figure 13.19).

Figure 13.19 Colostomy enema: ascending colon.

The patient experience

Subjectively, many patients are reticent about going to see their family doctor about symptoms associated with their ‘bottom’. In talking to the patient and explaining the procedure, it helps to be aware of the examination from their perspective and let them know you are aware. Many referred patients are of an age where comorbidities are likely to be a limiting factor and, in a number of cases, only by talking to the patient before the examination can this be properly assessed. The bowel preparation can leave the external anal margin feeling raw making intubation uncomfortable. Rectal intubation and the desire to evacuate is embarrassing and undignified. Careful control of the rate of barium infusion or gas insufflation can minimize the rectal discomfort.

Proctography

Defecation proctography provides dynamic imaging of the pelvic floor to assess the anatomy and dynamics of defecation (Hare et al., 2001). It can provide considerable weight to clinical decision making, such as whether surgery or conservative therapy would be more appropriate (Jones et al., 1998; Harvey et al., 1999).

Current defecation proctography methods range from utilizing rectal and small bowel contrast (Harvey et al., 1999) to what Kelvin and Maglinte (2001) and Altringer et al. (1995) describe as an extended examination incorporating bladder, small bowel, vaginal and rectal contrast. The standard examination described here can be performed and reported by a suitably trained radiographer.

Patients are predominantly female with symptoms of obstructed defecation syndrome (ODS) where individuals have difficulty in emptying their bowels. Symptoms of ODS often develop following injury during childbirth (Halligan, 2001). Proctography during pregnancy is contraindicated, not only because of the use of ionizing radiation, but also because the pregnancy and birth will have an effect on the pelvic floor, possibly altering the pelvic configuration and functionality (Halligan et al., 1996).

A number of alternative examinations complement defecating proctography (Dvorkin et al., 2005). These include:

Proctography technique

One hour before imaging the patient drinks 100 ml Baritop diluted with 200 ml water. Ingested contrast will demonstrate the pelvic small bowel during the examination to identify a possible enterocele. The examination begins with the patient supine on the table and the technique as outlined in Box 13.1 is followed.

As well as small bowel contrast, rectal and vaginal contrast is also used (Kelvin and Maglinte, 2001) (Figure 13.20). The separate use of small bowel contrast once an enterocele had been indicated at defecating proctography has been reported in a study (Kelvin et al., 1992), however, it was recognized that this would increase the resultant dose of the examination.

Figure 13.20 Defecating proctogram: demonstrating cystocele, enterocele, sigmoidocele, rectocele and rectoanal intussusception.

Image by Helen Carter.

In assessing pelvic prolapse, vaginal contrast will demonstrate during evacuation any displacement of the bladder or widening of the rectovaginal space (Low et al., 1999). To minimize the risk of extravasation (Blakeborough et al., 1997a, Chapman and Blakeborough, 1998), only 2–3 ml of barium need be used to identify the vaginal apex and whether it has prolapsed below the pubococcygeal line.

Bladder contrast (Altringer et al., 1995; Kelvin and Maglinte, 2001) can be administered intravenously or by catheterization; however, it need not and should not be used in all cases, and risk/benefit considerations should be given before the administration of intravenous contrast agent (Bettmann, 2005; Namasivayam et al., 2006).

Delayed, post complete rectal evacuation images are recommended as enteroceles often only become evident at the end of evacuation. If not almost or fully empty, re-screen following attempted evacuation in the toilet for a further 5 minutes – an anismus may prevent herniation of the small bowel (Kelvin et al., 1999; Kelvin and Maglinte, 2001).

Aftercare

Information would include warning of the whitish colored motions for a couple of days and that if they find they get constipated to take a mild laxative.

Interpretation of images

Interpretation of images considers the alterations in anorectal angle and position of anorectal junction in addition to the ability rapidly and completely to evacuate the contrast (Halligan, 2001). Prolapse of pelvic organs is considered in relation to the position of the pubococcygeal line and the extent of prolapse can be noted (Figures 13.21A, 13.21B).

Figure 13.21 (A) Defecating proctogram: demonstrating external prolapse sac containing prolapsed rectum. (B) Same patient following straining; additionally demonstrates prolapse of sigmoid colon.

Images by Helen Carter.

BOX 13.1 Proctography technique and imaging

Vaginal contrast administered

Left lateral position – intubate, infuse barium and ‘barium paste’

Right lateral position – images taken while resting, squeezing and straining; all of which must include the pubic symphysis and coccyx

Patient takes a seat while equipment changes to vertical position – specially adapted bedpan placed on footrest

Right lateral position sat on bedpan – mobile screen positioned to provide some seclusion for patient

Images taken at one frame per second while patient defecates as fast and completely as they can, again including the pubic symphysis and coccyx

When empty, take spot films of resting, squeezing and straining

Examination completed