Usefulness of an Intensive Bowel Cleansing Strategy for Repeat Colonoscopy After Preparation Failure

BACKGROUND: No consensus exists regarding the optimal bowel preparation regimen for patients with poor bowel cleansing at a previous colonoscopy. OBJECTIVE: We investigated the usefulness of an intensive cleansing regimen for repeat colonoscopy after previous failure of bowel preparation. DESIGN AND SETTING: A prospective observational study was performed in patients undergoing colonoscopy at a university-based, tertiary referral hospital. PATIENTS AND INTERVENTION: Outpatients with inadequate preparation at an index colonoscopy were offered a repeat colonoscopy and instructed to follow an intensive preparation regimen consisting of a low-fiber diet for 72 hours, liquid diet for 24 hours, bisacodyl (10 mg) in the evening of the day before the colonoscopy, and a split dose of polyethylene glycol (1.5 L in the evening before and 1.5 L in the morning on the day of the colonoscopy). MAIN OUTCOME MEASURES: The adequacy of bowel cleansing was assessed according to the Boston Bowel Preparation Scale (0 or 1 on any colon segment = inadequate bowel preparation). Procedural variables, detection rates for polyps and adenomas, compliance, and tolerability of the regimen were assessed. Satisfaction with the regimen was assessed with a 10-point visual analog scale. RESULTS: Of 83 patients with inadequate bowel preparation at colonoscopy, 51 underwent a second colonoscopy and were analyzed; 46 patients (90.2%) had adequate bowel cleansing at the second colonoscopy, with a mean (SD) total Boston Bowel Preparation Scale score of 7.43 (1.5) and scores of 2.31 (0.6) for the right colon, 2.49 (0.6) for the transverse colon, and 2.63 (0.6) for the left colon. Polyps, flat lesions, or flat lesions proximal to the splenic flexure were found in significantly more patients at the second colonoscopy than at the index colonoscopy. The global satisfaction score was 6.6 (2.7). LIMITATIONS: The study was limited because of its open observational design, possible patient learning effect for bowel preparation at the repeat colonoscopy, and the inclusion of only outpatients. CONCLUSIONS: An intensive regimen consisting of a low-fiber diet, bisacodyl, and a split dose of polyethylene glycol can achieve good colon preparation with an improved detection rate for polyps and adenomas in most patients who have had poor bowel cleansing at a previous colonoscopy.