Colon to Rectum
Endoscopy. 2023;55(9):822–35
Mandatory vs. optional split-dose bowel preparation for morning colonoscopies: A pragmatic non-inferiority randomized controlled trial
Background: The authors compared the effectiveness of optional split-dose bowel preparation (SDBP) with mandatory SDBP for morning colonoscopies in usual clinical practice.
Methods: Adult patients undergoing outpatient early morning (8:00 AM–10:30 PM) and late morning (10:30 AM–12:00 PM) colonoscopies were included. Written bowel preparation instructions were provided based on randomization: 1 group was instructed to take the bowel preparation (4 liters of polyethylene glycol solution) as a split dose (mandatory), while the comparator group was allowed the choice of SDBP or single-dose bowel preparation administered entirely on the day before (optional). The primary end point, using non-inferiority hypothesis testing with a 5% margin, was adequate bowel cleanliness measured by the Boston Bowel Preparation Scale (BBPS) and defined by a BBPS score ≥ 6.
Results: Among 770 randomized patients with complete data, there were 267 mandatory SDBP and 265 optional SDBP patients for early morning colonoscopies, and 120 mandatory SDBP and 118 optional SDBP patients for late morning colonoscopies. Optional SDBP was inferior to mandatory SDBP, with a lower proportion of adequate BBPS cleanliness for early morning colonoscopies (78.9% vs. 89.9%; absolute risk difference [aRD] = 11.0%, 95% confidence interval [CI]: 5.9–16.1%), but was not statistically different for late morning colonoscopies (76.3% vs. 83.3%; aRD = 7.1%, 95% CI: -1.5–15.5%).
Conclusions: Optional split-dose bowel preparation (SDBP) is inferior to mandatory SDBP in providing adequate bowel preparation quality for early morning colonoscopies (8:00 AM–10:30 AM), and probably inferior for late morning colonoscopies (10:30 AM–12:00 PM).
DOI: 10.1055/a-2070-5561