Curious About the Reliability of a Barium Enema

QUESTION: I am curious about the reliability of a barium enema in diagnosing
intestinal disease. If all the stuff they put in you is a dye, how does that
tell the doctors where disease may be present? What do they see on the x-rays
that permits them to arrive at any conclusions?
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ANSWER: Although frequently referred to as a "dye", the truth is barium is a
substance that is not transparent to x-rays, and shows up as a white mass
filling the large intestines. It provides a clear outline of the interior
surfaces of the colon and rectum, and can reveal the presence of growths, such
as cancerous tumors or benign polyps, and areas of inflammation, as well as
the small pockets or pouches that signify diverticulosis. During the
procedure, the barium is allowed to flow out, but some still remains clinging
to the walls of the intestine to provide another view to the examining
radiologist, and help in diagnosing any pathology present. The development of
colonoscopy, in which a flexible telescope-like instrument is used to view the
intestinal lining directly, has replaced the use of the barium enema in many
instances.