Patient compliance and suboptimal bowel preparation with split-dose bowel regimen in average-risk screening colonoscopy

Background: Although split-dose bowel regimen is recommended in colon cancer screening and surveillance guidelines, implementation in clinical practice has seemingly lagged because of concerns of patient compliance. Objectives: To assess patient compliance with the split-dose bowel regimen and assess patient-and preparation process-related factors associated with compliance and bowel preparation adequacy. Design: Prospective survey cohort. Setting: Tertiary care setting. Patients: Average-risk patients undergoing colonoscopy for colorectal cancer screening between August 2011 and January 2013. Main Outcome Measurements: Split-dose bowel regimen patient-reported compliance and bowel preparation adequacy with the Boston Bowel Preparation Scale score. Results: Surveys and Boston Bowel Preparation Scale score data were completed in 462 participants; 15.4% were noncompliant with the split-dose bowel regimen, and suboptimal bowel preparation ( score! 5) was reported in 16% of all procedures. White ( P = .009) and married ( P = .01) subjects were least likely to be noncompliant, whereas Hispanic subjects and those who reported incomes of US$75,000 or less were most likely to be noncompliant ( P = .004). Participants who were noncompliant with split-dosing were less likely to follow the other laxative instructions and more likely to have their colonoscopy appointment before 10: 30 AM. Compliance differed by bowel preparation type ( P = .003, chi(2) test), with those who used MiraLAX showing the highest compliance, followed by polyethylene glycol electrolyte solution and other bowel preparations. Noncompliance with split-dose bowel preparation ( odds ratio 6.7; 95% confidence interval, 3.2-14.2) was the strongest predictor of suboptimal bowel preparation. Limitations: Patient self-report, performed at tertiary care center. Conclusions: Overall, 1 in 7 patients do not comply with a split-dose bowel regimen. Ensuring compliance with the split-dose bowel regimen will reduce the risk of a suboptimal bowel preparation.