Split-dose 1 L polyethylene glycol (PEG) with ascorbate is non-inferior to split-dose PEG with sodium picosulfate and...

Post-marketing studies comparing low-volume polyethylene glycol (PEG)-based regimens are limited. This randomized study aimed to compare the efficacy and tolerability of a novel 1-L low-volume PEG-based preparation: 1 L PEG+Asc (PEG3350, sodium ascorbate, sodium sulfate, ascorbic acid, sodium chloride, and potassium chloride) with PEG+SPMC (PEG3350, sodium chloride, potassium chloride and sodium sulfate, sodium picosulfate, magnesium oxide, citric acid, and aspartame), prior to routine colonoscopy at an Australian tertiary referral center.

Outpatients undergoing colonoscopy were randomized to receive either split-dose 1 L PEG+Asc or split-dose PEG+SPMC. Bowel preparation quality using the Boston Bowel Preparation Scale (BPPS), modified Aronchick scores, procedure time, cecal intubation, and adenoma detection rates were recorded. Patient compliance and tolerability were captured using a standardized questionnaire.

A total of 173 patients were randomized, of whom 164 completed the study and were allocated to 1 L PEG+Asc (n = 82) or PEG+SPMC (n = 82). Non-inferiority of 1 L PEG+Asc was demonstrated with 89% achieving successful preparation (total BPPS ≥6 and each sub-score ≥2) compared with 85.4% in the PEG+SPMC group, resulting in an estimated difference of 3.7% (95% CI -6.6% to 13.9%). The median BBPS was non-inferior in all colonic segments with 1 L PEG+Asc (BBPS 3 [interquartile range 2-3]) vs PEG+SPMC (BBPS 2 [interquartile range 2-3]). More 1 L PEG+Asc patients reported moderate to severe nausea (P = 0.028), but overall tolerability was similar.

The quality of bowel preparation achieved with 1 L PEG+Asc is non-inferior to that with PEG+SPMC, with similar tolerability outcomes. Further studies are required in patients at risk of suboptimal bowel preparation.