In certain Asian countries, guidelines recommend 2-L polyethylene glycol (PEG) without any additions as the standard bowel preparation (BP) regimen before colonoscopy.

A new study published in the Journal of Digestive Diseases investigated the efficacy of the split-dose 4-L PEG regimen on the quality of BP in Asian patients with previous colorectal surgery.

In this single-center, prospective, randomized-controlled, blinded study, 187 patients with previous colorectal surgery were randomized to either a routine, morning-only 2-L PEG (2-MO) group or a split-dose 4-L PEG (4-SD) group. The primary outcome was the rate of successful BP, while secondary outcomes were polyp detection rate (PDR), adenoma detection rate (ADR), patient compliance, satisfaction, tolerability, willingness to repeat the preparation, and difficulty of the BP process.

The results revealed that the rate of successful BP in the 4-SD group was higher relative to the 2-MO group. Additionally, patient satisfaction of the BP process in the 4-SD group was superior to that of the 2-MO group. On the other hand, no significant differences were detected in PDR, ADR, patient compliance, tolerance, willingness to repeat the preparation or difficulty of the BP process among the groups.

Hence, it was inferred that 4-SD PEG regimen is superior to a routine, morning-only 2-L PEG regimen for bowel preparation in patients with previous colorectal surgery.