Split-dose 4-L polyethylene glycol regimen for patients with previous colorectal surgery in bowel preparation before colonoscopy: A randomized, controlled, single-blind study

OBJECTIVE: We aimed to investigate the efficacy of a split-dose 4-L polyethylene glycol (PEG) regimen for the quality of bowel preparation in Asian patients with previous colorectal surgery for colorectal cancer (CRC). METHODS: This was a prospective, single-center, randomized controlled, endoscopist-blinded study. Patients with previous colorectal surgery for CRC were randomly allocated to a routine, morning-only 2-L PEG (2-MO) group or a split-dose 4-L PEG (4-SD) group. The primary outcome was a successful bowel preparation rate. Secondary outcomes were polyp detection rate (PDR), adenoma detection rate (ADR), patient compliance, satisfaction, tolerance, willingness to repeat the preparation and difficulty of the bowel preparation process. RESULTS: In total, 187 patients were included (93 in the 2-MO group, 94 in the 4-SD group) in this study. The rate of successful bowel preparation in the 4-SD group was higher than in the 2-MO group (89.4% vs 66.7%, P < 0.001) in an intention-to-treat analysis according to the Aronchick score. Patients' satisfaction with the bowel preparation process in the 4-SD group was superior to that in the 2-MO group (93.4% vs 82.2%, P = 0.021). No significant differences were detected in PDR, ADR, patient compliance, tolerance, willingness to repeat the preparation or difficulty of the bowel preparation process. CONCLUSIONS: The 4-SD PEG regimen was superior to a routine, morning-only 2-L PEG preparation for bowel preparation in an Asian population with previous colorectal surgery.