Diverse signs may be seen on barium enema in the various forms of colitis. Barium enema is only reasonably specific in the diagnosis of Crohn's disease and ulcerative colitis once the other possible diseases have been excluded from consideration by biopsy, microscopy, culture, or therapeutic trial. In particular, campylobacter colitis has proved to be such a common entity that many patients originally thought to have had one attack of ulcerative colitis, ischemic colitis, or Crohn's colitis may never have had these diseases. Many of the relatively specific signs can be seen in a variety of conditions. For example, aphthae in the colon may be seen in Crohn's disease, yersinia enterocolitis, Behçet's syndrome, amebiasis, ischemia, tuberculosis, and campylobacter colitis. Continuity of disease is characteristic in ulcerative colitis. Nevertheless, patches of healing may occur, so that a rare patient may be seen during a resolving attack of ulcerative colitis in whom only scattered patches of active disease can be seen on barium enema. In general, few radiologic signs on barium enema are truly specific for one disease, with penumatosis cystoides coli being an exception to this rule. However, the sensitivity of barium enema with currently available materials for double-contrast techniques is such that radiology continues to be useful at present in diagnosing the colitides and in managing patients.
