Effectiveness and safety of 1-L PEG-ASC versus other bowel preparations for colonoscopy: A meta-analysis of nine randomized clinical trials

Background and aims: A 1-L polyethylene glycol plus ascorbate (PEG-ASC) preparation has been recently developed to improve patients’ experience in colonoscopy. This meta-analysis aimed to evaluate the effectiveness and safety of 1-L PEG-ASC compared with those of other bowel preparations for colonoscopy. Methods: MEDLINE, Embase, Scopus, and the Cochrane Library were systematically searched for randomized controlled trials comparing 1-L PEG-ASC with other bowel preparations published through July 2022. A random-effects model was applied for pooling the results; heterogeneity was expressed as I2. Results: Nine studies met the inclusion criteria and were included. The analysis showed significantly higher cleansing success (CS) (OR = 1.50; 95% CI = 1.25–1.81; p < 0.01, I2 = 0%) and right-colon high-quality cleansing (HQC) (OR = 1.67; 95% CI = 1.21–2.31; p < 0.01, I2 = 43%) with 1-L PEG-ASC compared to the other preparations. The pooled estimate of the adenoma detection rate (ADR) did not significantly differ between the two groups either in the overall (OR = 1.02; 95% CI = 0.87–1.20; p = 0.79, I2 = 0%) or split-dosing regimen subgroup analysis (OR = 0.99; 95% CI = 0.84–1.18; p = 0.94, I2 = 0%). A significantly higher pooled estimate of the number of patients with adverse events (AEs) (OR = 1.51; 95% CI = 1.23–1.84; p<0.01, I2 = 0%) and incidence of AEs (IRR=1.33; 95% CI = 1.11–1.58; p<0.01, I2 = 71%) was observed with 1-L PEG-ASC than with the other preparations. No serious AEs or deaths occurred. Conclusions: Compared to other preparations, 1-L PEG-ASC yielded higher overall CS, higher right-colon HQC rates, and similar ADR. The number of patients with AEs and incidence of the total AEs were significantly higher with 1-L PEG-ASC in the absence of serious AEs.