Keeping the cecum clean: a randomized, prospective, placebo-controlled trial of loperamide as part of preparation for colonoscopy.

Coating of the cecum with sticky bile causes a problem with inspection of the mucosa during colonoscopy. This study aimed to see whether 4 mg of loperamide taken after colonoscopy preparation would delay the passage of bile and improve the quality of cecal preparation. Patients undergoing office colonoscopy were included. Patients with incomplete colonoscopies or right colectomy were excluded. This study was a prospective, randomized, double-blinded, and placebo-controlled trial. Either 2 placebo capsules or 2 loperamide capsules were taken after gut lavage, as soon as the passage of liquid stool ceased. Cecal photographs were scored in a blinded fashion. The primary outcomes measured were the quality of cecal preparation on a scale of 1 to 5 and overall preparation on a scale of 1 to 4. Ninety-eight patients took loperamide (50 men, 48 women) and 102 took placebo (57 men, 45 women). Mean ages of the loperamide group were: men, 61.9 ± 11.9 years, and women, 61.8 ± 10.0 years; and mean ages of the placebo group were: men, 62.5 ± 12.1 years, and women, 58.6 ± 9.8 years. Over 90% of patients used a polyethylene glycol-based preparation. Thirteen of 102 (12.7%) placebo cases had a dirty or coated cecum (score 4 or 5). In the loperamide group, this number was 2 of 98 (2.0%; p = 0.0041). Nineteen placebo cases (18.6%) had an overall fair/poor preparation in comparison with 9 of the loperamide group (9.2%; p = 0.0543). Days to first bowel movement were 2.4 ± 1.1 for loperamide and 2.5 ± 1.7 for placebo (p = 0.7224). Fifty-eight percent of loperamide patients had polyps, and 74% of these patients had multiple polyps; 67% of placebo patients had polyps, but only 54% of these patients had multiple polyps (vs loperamide, p = 0.0183). Judicious use of loperamide can significantly improve the quality of cecal preparation and may increase polyp yield.