Radiological procedure to provide imaging of the colon. After bowel preparation, barium-containing contrast medium and air are introduced per rectum. The contrast media tends to coat the lining of the bowel while the air distends the bowel. This is the most common form the investigation and is referred to as a double-contrast barium enema. In the absence of air insufflation, the procedure is known as a single-contrast barium enema.
X-ray exposures of the abdomen, are generally performed fluoroscopically, to outline the internal surface of the colon and rectum. This is possible because the radio-opaque contrast media outlines the bowel mucosa as it is adjacent to radio-lucent air.
An injection of an antispasmodic agent is usually given (Buscopan is most often the agent of choice in the UK, but Glucagon may be used) to help obtain better quality images and to help alleviate patient discomfort.
Used in the investigation and diagnosis of lower GI symptoms. Usually combined with sigmoidoscopy as the rectum and early sigmoid are hard to image well.
Likely to be supplanted by CT colonoscopy.
- Requires bowel preparation
- Uncomfortable and invasive
- Need to be able to retain the contrast and air (a problem if weak sphincters).
- Cannot biopsy.
- Less liked by patients.
- Not as accurate as optical colonoscopy (see below).
The difficulty with defining sensitivity is that it depends on the disease being studied (e.g. cancer vs diverticular disease) and the particular group of patients being investigated.
The exact nature of a lesion, e.g. a stricture, may be hard to tell on a barium enema, so sensitivity can be judged on different end-points: the demonstration rate and the diagnosis rate. The Royal College of Radiology has set audit standards at a 95% demonstration rate and a 90% diagnosis rate.
In one study, comparison of three modalities for colorectal tumours gave a sensitivity 35-48% and sensitivity of about 90% (depending on size of lesion).
See also meta-analysis .
- ↑ Bosworth HB, Rockey DC, Paulson EK, Niedzwiecki D, Davis W, Sanders LL, et al. Prospective comparison of patient experience with colon imaging tests. The American journal of medicine 2006;119(9):791-9. (Direct link – subscription may be required.)
- ↑ Irvine EJ, O'Connor J, Frost RA, Shorvon P, Somers S, Stevenson GW, et al. Prospective comparison of double contrast barium enema plus flexible sigmoidoscopy v colonoscopy in rectal bleeding: barium enema v colonoscopy in rectal bleeding. Gut 1988;29(9):1188-93.
- ↑ Tawn DJ, Squire CJ, Mohammed MA, Adam EJ. National audit of the sensitivity of double-contrast barium enema for colorectal carcinoma, using control charts For the Royal College of Radiologists Clinical Radiology Audit Sub-Committee. Clinical radiology 2005;60(5):558-64. (Direct link – subscription may be required.)
- ↑ Rockey DC, Paulson E, Niedzwiecki D, Davis W, Bosworth HB, Sanders L, Yee J, Henderson J, Hatten P, Burdick S, Sanyal A, Rubin DT, Sterling M, Akerkar G, Bhutani MS, Binmoeller K, Garvie J, Bini EJ, McQuaid K, Foster WL, Thompson WM, Dachman A, Halvorsen R. Analysis of air contrast barium enema, computed tomographic colonography, and colonoscopy: prospective comparison. Lancet. 2005;365(9456):305-11. (Direct link - subscription may be required.)
- ↑ Rosman AS, Korsten MA. Meta-analysis comparing CT colonography, air contrast barium enema, and colonoscopy. The American journal of medicine 2007;120(3):203-210.e4. (Direct link – subscription may be required.)