1 versus 2 L PEG/Asc for bowel preparation in patients with hematochezia: a multicenter, prospective, randomized,...

Patients with hematochezia often present with inadequate bowel preparation, which compromises the accuracy of colonoscopy. Despite this clinical challenge, evidence guiding optimal preparation strategies for this population is limited.

We directly compared the efficacy and safety of ultra-low-volume (1 L) polyethylene glycol/ascorbic acid (PEG/Asc) versus low-volume (2 L) PEG/Asc in patients undergoing colonoscopy for hematochezia.

In a prospective, randomized, multicenter non-inferiority trial, patients received either 1 or 2 L PEG/Asc using standard split-dose regimens.

Bowel preparation quality was assessed using the Boston Bowel Preparation Scale (BBPS). Secondary outcomes included patient satisfaction, adverse events, colonic bleeding source identification rate, and adenoma detection rate (ADR).

In total, 184 patients were analyzed. Successful bowel cleansing was achieved in 78.3% of the 1 L PEG/Asc group and 76.1% of the 2 L PEG/Asc group, confirming non-inferiority. The mean BBPS score was higher with 1 L PEG/Asc (6.87 vs 6.30; p = 0.053). Patient satisfaction favored the 1 L PEG/Asc group, although the difference was not statistically significant. Colonic bleeding source identification was slightly higher in the 1 L PEG/Asc group than in the 2 L PEG/Asc group, but the difference did not reach statistical significance (82.4% vs 73.6%; p = 0.165). Completion rates, adverse events, and ADR were similar between groups.

Ultra-low-volume (1 L) PEG/Asc is as effective and safe as 2 L PEG/Asc for bowel preparation in patients with hematochezia. Bowel cleansing and satisfaction were higher with the 1 L PEG/Asc regimen without statistically significant differences, supporting its use as a practical alternative.

The study was registered with the Clinical Research Information Service, Republic of Korea, a primary registry in the WHO Registry Network (registration number: KCT0006124).