Comparison of a split-dose bowel preparation with 2 liters of polyethylene glycol plus ascorbic acid and 1 liter of polyethylene glycol plus ascorbic acid and bisacodyl before colonoscopy.

BACKGROUND AND AIMS: Recently, a low-volume polyethylene glycol formulation containing ascorbic acid (PEG-Asc) has proven as safe and effective as traditional 4-L PEG solutions for colonoscopy preparation. However, currently available aqueous purgative formulations are poorly tolerated. The aim of this study was to compare a split-dose 2-L PEG-Asc formulation and a 1-L PEG-Asc formulation with bisacodyl (10 mg) to determine the quality of bowel cleansing and patient tolerability.

METHODS: A single-center, randomized, observer-blinded study was performed between May 2015 and September 2015. Two hundred outpatients referred for colonoscopy were prospectively enrolled and assigned to either the split-dose 2-L PEG-Asc group or the 1-L PEG-Asc with bisacodyl 10-mg group. The Boston Bowel Preparation Scale (BBPS) and Aronchick Bowel Preparation Scale (ABPS) were used to evaluate bowel cleansing. The tolerability of the regimens and satisfaction of patients was determined based on a questionnaire.

RESULTS: Two hundred patients received either 2-L PEG-Asc or 1-L PEG-Asc with bisacodyl. Regarding colon cleansing outcome (BBPS and ABPS), the 1-L PEG-Asc with bisacodyl group showed similar but non-inferior results compared with the 2-L PEG-Asc group on both BBPS (6.92 ± 1.63 vs 6.57 ± 1.37; P = .103) and ABPS (96% vs 95%; P = 1.000) scales. Tolerability was similar for both 1-L PEG-Asc with bisacodyl and 2-L PEG-Asc.

CONCLUSIONS: 1-L PEG-Asc is a suitable alternative to low-volume bowel preparation for colonoscopy. Our study showed that the 1-L PEG-Asc plus bisacodyl preparation has comparable tolerability and results in adequate colon cleansing. Bowel preparation with bisacodyl and 1-L PEG-Asc is a suitable alternative to low-volume bowel preparation for colonoscopy. (Clinical trial registration number: NCT02980562.).