Our initial attempts at implementing a high‐volume clinic were impeded by the quality of colon preparation. While two Fleet enema preparations were generally easy to administer and well tolerated, the results were frequently poor. Current studies are limited and opinions vary regarding the most effective bowel preparation. The purpose of this study was to compare three forms of bowel preparation for screening flexible sigmoidoscopy. All patients scheduled for screening flexible sigmoidoscopy were given one of three colon preparations: two Fleet enemas; magnesium citrate orally the evening before, clear liquid diet and two Dulcolax suppositories the day of the exam; or magnesium citrate orally the evening before, clear liquid the day of the exam, and two Fleet enemas 1 hour before the procedure. Examinations were performed using a video flexible sigmoidoscopy by specialty trained gastroenterologists. Physicians were asked to rate the preparations as excellent, good, fair, or poor according to explicit criteria, and to document depth of insertion. Results showed that the magnesium citrate and Fleet enema preparation was excellent for 70% of patients, allowing for greater depth of insertion. Need for repeat examination due to poor preparation was infrequent with this group and patient tolerance of the preparation was acceptable.