Interval between cleansing enema and barium examination of the colon.

A prospective, randomized, blinded study was conducted to determine the optimal length of time a patient should wait after evacuating a cleansing enema prior to undergoing barium enema. Evaluation of overhead films, graded for the amount of retained fluid and fecal material, detected no significant improvement in colon examinations that were delayed longer than 30 min. Patient acceptance and scheduling can be improved by eliminating unnecessary waiting.