Detection of intracolonic lesion by barium contrast enema. The importance of adequate colon preparation to diagnostic accuracy.

Frequently, the clinical significance of the barium contrast enema is minimal because of inadequate colon preparation prior to examination. The frequency of false-positive routine barium enemas was 17% in 230 consecutive patients who underwent colonoscopy for removal of specific radiographically identified polypoid colon lesions. Initial barium enema inaccuracies were documented with postendoscopic air-contrast radiography in colons that were endoscopically proved to be mechanically clean following a two-day colon preparation. These results suggest that more emphasis on a two-day colon preparation, before the initial barium contrast enema, would substantially reduce the frequency of false-positive interpretations.