Reliability of routine double-contrast examination (DCE) of the large bowel in polyp detection: a prospective clinical study.

A total of 2,118 consecutive patients, examined with double-contrast examination of the large bowel (DCE), were evaluated radiographically, clinically, and endoscopically for up to 48 months. A total of 402 polyps were diagnosed during the follow-up period. Of these, 307 were revealed at the first DCE and 95 at subsequent endoscopy or autopsy. The accuracy of the DCE for demonstrating or excluding patients with polypoid lesions of the colon was 97%, whereas the predictive value of a positive DCE report was 96% and a negative one, 97%. However, the ability to demonstrate every known polyp at DCE was only 63%, although the probability of a polypoid lesion demonstrated at DCE being a true polyp was 92%.