When Is a Barium Enema (BE) Necessary?
The indications for barium enemas remain a controversial issue. Colonoscopy,
which involves inserting a fiber optic tube into the rectum and passing it
through the large bowel, has taken over as the definitive way of examining
the large bowel. That test, though significantly more costly than the BE, is
generally considered more accurate.
Its real advantage is the ability to biopsy and even remove polyps (small
growths that are usually noncancerous, but not always) through the same
tube. Sedation is generally needed and, when effective, causes complete
amnesia of the event, which is a good thing.
Though not the "gold standard," BE is considered an excellent test for
finding cancers of the colon, for looking at various inflammatory conditions
such as diverticulitis, and for discovering polyps, especially with the air
contrast technique. Now and then, the radiologist may be asked to actually
treat a condition known as intussuseption.
In this rare situation, the end of the small bowel rolls into the beginning
of the large bowel. One tube slides inside the other, so they block each
other. The remedy is pressure from the outside to push the inside tube back
out of the outside tube (reduce the intususseption).
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Alternatives
Colonoscopy is the principle alternative to BEs. Patients who are too
debilitated, or are unable to cooperate enough to have BEs, can have
alternative abdominal and pelvic CT scans that detect major large bowel
pathology. There is a very new and exciting test called virtual colonoscopy
that allows the radiologist to examine the large bowel almost like a
computer game.
Risks and Potential Complications
The good news is that there are few complications to barium enemas. Most
complications arise from the insertion of the enema tube and the inflation
of the little balloon at the enema tip. Very rarely, patients may be
allergic to the latex in the balloon. Overinflation of the balloon can
result in tearing of the rectal wall, which can be a very serious
complication. This complication is most apt to occur when the lining of the
rectum is inflamed, such as in ulcerative colitis. It would be very unusual
to overinflate a normal rectum.
