The outcome of a second preparation for colonoscopy after preparation failure in the first procedure

Background: There are scant data regarding the outcome of consecutive repeated procedures in patients who failed to adequately clean their colon for colonoscopy. Objective: To investigate the outcome of a second colonoscopy after preparation-associated failure of the first colonoscopy. Design and Setting: A retrospective study in a tertiary-referral center. Patients: All patients with failure of colonoscopy because of poor preparation within a 1-year period. Results: Of a total of 6990 colonoscopies performed during the study period, 307 procedures (4.4%) failed because of inadequate preparation. Data on subsequent repeated colonoscopies were available for 235 patients. The repeated procedure again failed because of unsatisfactory preparation in 54 of these patients (23%). The failure rate in subsequent third and fourth colonoscopies was also high (more than 25%). Of the various patient and procedure-related parameters examined, only the use of calcium channel blockers (CCB) was found to be predictive of a failed repeated preparation (odds ratio [OR] 3.2 [95% CI, 1.6-6.3], P < .001). In contrast, a next-day colonoscopy after failure of the index procedure was associated with a reduced risk of unsatisfactory second preparation (OR 0.31 [95% CI, 0.1-0.92], P = .03). Limitations: Validated data on the specific bowel purgatives used were not available. Conclusions: Almost a fourth of patients with an unacceptable colonic preparation will also fail the repeated colonoscopy, and patients who use CCB are at particular risk for failure. Strategies to manage this difficult-to-treat patient group should be investigated and may possibly include a preference for next-day colonoscopy.