Combination of bisacodyl suppository and 1L polyethylene glycol plus ascorbic acid (PEG-Asc) is a non-inferior and comfortable regimen compared to 2L PEG-Asc.

Appropriate bowel cleansing before colonoscopy is an important factor in increasing the detection rate of lesions. Low-volume polyethylene glycol (PEG) plus ascorbic acid (PEG-Asc) reduces the dosage of bowel preparation agent, but is still presents discomfort to patients.The primary aim of our study was to compare the efficacy of bowel cleansing between the 2L PEG-Asc (control) and 1L PEG-Asc with bisacodyl suppository (suppository) groups, and the secondary aim was to investigate complications and tolerability between the two groups.This was a single-center prospective randomized controlled study. We identified 168 patients scheduled for colonoscopy between August 2017 and January 2018 and randomly assigned them to the control or the suppository groups. The efficacy of bowel cleansing was assessed using the Boston Bowel Preparation Scale (BBPS), and side effects were surveyed using questionnaires.No significant difference was detected in baseline characteristics including insertion and withdrawal times, and adenoma detection rates between the two groups. The total BBPS score was 7.93 ± 1.06 and 7.74 ± 1.02 in the control and suppository groups, respectively (P = 1.02). The incidence of abdominal pain and nausea was not statistically different, whereas that of sleep disturbance and anal discomfort was higher in the control group. (P = 0.00) CONCLUSIONS: 1L PEG-Asc with bisacodyl suppository resulted in an equivalent bowel cleansing outcome with reduced patient discomfort compared to 2L PEG-Asc. Therefore, PEG-Asc with bisacodyl suppository represents a potential alternative and increases patient' compliance to bowel preparation.