Predictors and colonoscopy outcomes of inadequate bowel cleansing: a 10-year experience in 28,725 patients

Authors Fadi Abu Baker, Amir Mari, Smadar Nafrin, Muhammed Suki, Baruch Ovadia, Oren Gal, Yael Kopelman.


Background Inadequate bowel preparation is still the main obstacle to a complete colonoscopy in many patients and necessitates many repeated procedures. We aimed to identify risk factors associated with inadequate bowel preparation and to better characterize these patients.

Methods This was a retrospective study that reviewed electronic reports of colonoscopy procedures over a 10-year period. Patients were divided into 2 groups: adequate vs. non-adequate bowel preparation. A multivariate analysis was performed to identify variables associated with inadequate bowel preparation, including age, sex, setting (inpatient/outpatient), preparation regimen and procedures’ indications. We examined the effect of inadequate preparation on colonoscopy quality indicators.

Results Of the 28,725 patients included in the study, 6,702 (23.3%) had inadequate bowel preparation. In the multivariate analysis, advanced age (odds ratio [OR] 1.015, 95% confidence interval [CI] 1.013-1.017; P<0.01), male sex (OR 1.353, 95%CI 1.286-1.423; P<0.01) and a minority population (OR 1.635, 95%CI 1.531-1.746; P<0.01) were significantly associated with inadequate bowel preparation. The inpatient setting was among the most prominent factors associated with inadequate bowel preparation (OR 2.018, 95%CI 1.884-2.163; P<0.01). Adequate bowel preparation was associated with a higher polyp detection rate (26.8% vs. 23.6%; OR 1.22, 95%CI 1.109-1.347; P<0.01) and colorectal cancer (2.8% vs. 2.4%; OR 1.402, 95%CI 1.146-1.716; P<0.01), and higher frequencies of cecal (96.4% vs. 73.5%; OR 2.243, 95%CI 2.095-2.403; P<0.01) and terminal ileum intubation (8.1% vs. 5.4%; OR 1.243, 95%CI 1.088-1.434; P<0.01).

Conclusion We outlined various factors associated with inadequate bowel preparation and confirmed its adverse effect on colonoscopy quality indicators.

Keywords Bowel preparation, predictors, outcomes

Ann Gastroenterol 2019; 32 (5): 457-462

Original Articles