Background: The factors associated with inadequate bowel cleansing leading to colonoscopy failure are not well known.
Objective: We conducted a multicentre, prospective, observational case-control study in order to identify these factors.
Methods: Investigators included one patient with colonoscopy failure due to inadequate bowel cleansing (failure group) and the following patient with complete colonoscopy (success group). Data related to demographics, medical history, and preparation were collected and compared. Factors associated with bowel cleansing failure were identified by multivariate logistical regression analysis.
Results: A total of 101 gastroenterologists included 202 patients from 1 November 2009 to 15 January 2010. There was no difference between both groups with regards to baseline characteristics. In univariate analysis, factors significantly associated with bowel cleansing failure were vomiting during preparation (p = 0.0007), incomplete intake of the preparation (p = 0.002), and constipation (p = 0.02). Type and timing of preparation were not significantly different between groups. In multivariate analysis, incomplete intake of the preparation (OR 4.5, 95% CI 1.2-17.3), constipation (OR 4.2, 95% CI 1.2-14.9), and treatment with neuroleptics or antidepressants (OR 9.9 (95% CI 1.4-71.0) were independent predictors of colonoscopy failure.
Conclusions: Factors associated with bowel cleansing failure were incomplete intake of the preparation, constipation, and treatment with psychotropic drugs. Interventions to reduce poor colonoscopy preparations should be targeted at these at-risk patients.
Keywords: Bowel preparation; inadequate bowel cleansing; risk factors.