BACKGROUND: Anecdotally, we observed that patients who had previous colonoscopies were less likely to follow newly implemented split-dose bowel preparation (SDBP) instructions. We investigated whether the indication for colonoscopy is an independent factor for achieving high quality bowel preparation among patients asked to follow SDBP.
METHODS: We performed a retrospective study of data from 1478 patients who received outpatient colonoscopies in 2014 (the year of SDBP implementation) at our Veterans Affairs Medical Center. We collected information related to demographics and factors known to affect bowel preparations. Reasons for colonoscopy were dichotomized into surveillance (previous colonoscopy) vs. non-surveillance (positive occult blood test or screening). Bowel preparation quality was scored using the Boston Bowel Preparation Scale (BBPS), and was categorized as either excellent vs. not excellent (BBPS≥7 vs. BBPS<7), or adequate vs. inadequate (BBPS≥6 vs. BBPS<6).
RESULTS: Bowel preparation quality was excellent in 60% of colonoscopies and adequate in 84% of colonoscopies. Thirty-six percent (535) were surveillance colonoscopies. In multivariate logistic regression analysis, more patients in the non-surveillance group achieved excellent (OR 0.8 ; 95% CI [0.7-0.8], P <0.0001) and adequate (OR 0.8 ; 95% CI [0.7-0.9], P <0.006) bowel preparation than did patients in the surveillance group.
CONCLUSION: Patients with a prior colonoscopy might not follow the split-dose bowel preparation instructions. Educational interventions emphasizing the benefits of SDBP in this group of patients may help ensure compliance and prevent the habitual use of day-before preparations.
