Increasing the low residue diet to 3 days does not improve the bowel cleansing in hard to prepare patients: Post hoc analysis of a randomized controlled trial.

BACKGROUND: Recent evidence suggests that the number of low residue diet (LRD) days does not influence the bowel cleansing quality in non-selected patients. However, there are not data in the subgroup of patients with risk factors of inadequate bowel cleansing. OBJECTIVE: The aim of this study was to assess whether a 3-day LRD improved the bowel cleansing quality in patients with risk factors of poor bowel cleansing. PATIENTS AND METHODS: Post hoc analysis of a randomized controlled trial carried out between December 2017 and March 2018 in a tertiary care hospital. Patients with high risk of poor bowel cleansing were selected following a validated score. The patients were randomized to the 1-day LRD or 3-day LRD groups. All patients received a 2-L split-dose of polyethylene glycol plus ascorbic acid. Intention-to-treat (ITT) and per-protocol (PP) analyses were conducted for the main outcome. RESULTS: 135 patients (1-day LRD group=67, 3-day LRD=68) were included. The rate of adequate cleansing quality was not significantly different between the groups in the ITT analysis: 76.1%, 95% CI: [64.6-84.8] vs. 79.4%, 95% CI: [68.2-87.4]; odds ratio (OR) 1.2, 95% CI [0.54-2.73]) or in the PP analysis: 77.3%, 95% CI: [65.7-85.8] vs. 80.3%, 95% CI: [69.0-88.3]; OR 1.2, 95% CI [0.52-2.77]). Compliance with the diet or cleansing solution, satisfaction or difficulties with the LRD and the polyp/adenoma detection rates were not significantly different. CONCLUSION: Our results suggest that 1-day LRD is not inferior to 3-day LRD in patients with risk factors of inadequate bowel cleansing.

Risk factors for inadequate bowel preparation: a validated predictive score.

Background and study aim Inadequate bowel cleansing negatively affects the efficiency of colonoscopy in routine clinical practice. The aim of this study was to design and validate a predictive model for inadequate bowel cleanliness. Patients and methods The model was built from 667 consecutive outpatients (development cohort) who were prospectively scheduled for colonoscopy between June and September 2014. The validation cohort included 409 outpatients who underwent colonoscopy between October and December 2014. Cleansing was evaluated using the Boston Bowel Preparation Scale (BBPS). Bowel preparation was administered on the same day as the examination. Results In the development cohort, BBPS was adequate in 541 patients (81.1 %). At multivariate analysis, antidepressants (odds ratio [OR] 4.25, 95 % confidence interval [CI] 1.91 - 9.47), co-morbidity (OR 3.35, 95 %CI 2.16 - 5.18), constipation (OR 2.09, 95 %CI 1.29 - 3.40), and abdominal/pelvic surgery (OR 1.60, 95 %CI 1.03 - 2.47) were independent predictors for inadequate cleansing. The model built with these variables showed an area under the curve of 0.72 in the development cohort and 0.70 in the validation cohort. A cutoff of 1.225 predicted inadequate bowel preparation with a sensitivity, specificity, positive predictive value, and negative predictive value of 60.3 % (95 %CI 51.6 - 68.4), 75.4 % (95 %CI 71.6 - 78.9), 36.4 % (95 %CI 30.1 - 43.1), and 89.1 % (95 %CI 85.9 - 91.6) in the development cohort, and 50.0 % (95 %CI 38.1 - 61.9), 80.0 % (95 %CI 75.3 - 84.2), 35.7 % (95 %CI 26.4 - 45.6), and 87.9 % (95 %CI 83.7 - 91.3) in the validation cohort. Conclusion A simple score may assist the clinician in predicting which patients are at high risk of inadequate bowel cleanliness. This may guide changes in bowel preparation strategy accordingly.