Radiologic recognition of colonic diverticula simulating polyps.

The differentiation of colonic polyps and diverticula on the double-contrast barium enema is generally straightforward, using current diagnostic criteria. However, diverticula may be misinterpreted on the double-contrast barium enema as polyps when they appear uncommonly as filling defects within the barium pool. As a result of such erroneous interpretation, the patient may subsequently undergo costly and inconvenient repeat barium enema or colonoscopy. Carefully studied scout films, oblique views, compression spot images, and postevacuation films generally can differentiate these diverticula from polyps. The usual reason that a diverticulum assumes the appearance of a polyp is that it contains impacted stool.