High quality bowel cleansing with ultralow volume laxatives: a multicenter noninferiority randomized clinical trial

Aims High-quality bowel preparation enhances lesion detection in colonoscopy compared to average-quality cleansing, ensuring accurate risk stratification, and determining appropriate follow-up intervals. While low-volume laxatives have shown similar efficacy to traditional high-volume preparations, they offer the added benefit of improved patient tolerance. However, limited evidence exists comparing ultralow-volume laxatives for achieving high-quality bowel cleansing. This study aimed to compare the efficacy of 1-liter of polyethylene glycol with ascorbate (1L-PEGA) versus sodium picosulfate with magnesium citrate (SPMC) in achieving high-quality bowel cleansing, using a split-dose regimen across various colonoscopy indications.

Methods We conducted a multicenter, parallel-group, randomized, non-inferiority clinical trial targeting individuals scheduled for colonoscopy, regardless of indication. Participants were randomized to either 1L-PEGA or SPMC in a split-dose regimen. The endoscopists were blinded to the treatment allocation. The primary outcome was the frequency of High-quality bowel cleansing, using the Harefield Scale (HS), defined as all bowel segments scoring 3 or 4 points. Secondary outcomes included lesion detection rates, patient tolerance, and adverse events. The non-inferiority of PEG1A compared to PSCM, both with an estimated 50% high-quality cleansing rate, a 10% margin, 90% power, and a one-sided 2.5% alpha error. NCT04598880

Results A total of 1186 individuals were included in the study, 589 patients receiving 1L-PEGA and 597 SPMC across 11 Spanish hospitals. Median age 60.3 years (P25: 53.6; P75: 66.3), the reason for colonoscopy was screening 46.2%, follow-up 31.8% and symptoms 17.6%. A chronic disease was present in 26.6% of the subjects. Baseline characteristics were comparable between both groups. Global high-quality cleansing rates were non-inferior and also significantly higher with 1L-PEGA compared to SPMC (61.5% vs. 32.1%; p<0.001), with an absolute risk difference of 29.5% (95% CI, 24–34.9, p<0.001). The adenoma detection rate (ADR) was also significantly higher in the 1L-PEGA group (49.4%) compared to SPMC (43.3%), with a relative risk of 1.14 (95% CI, 1.01–1.29). Mean adenomas per patient (MAP) were greater in the 1L-PEGA group (1.11±1.66) compared to SPMC (0.99±1.69), with a mean difference of 0.12. There were no significant differences between groups in the detection of high-risk adenomas, serrated lesions, or cancers. Tolerability was better for SPMC, as reflected by fewer nausea (17.6% vs. 8.5%; p<0.001), vomiting (8.2% vs. 3.0%; p<0.001) and thirst (11.8% vs. 3.0%; p<0.001) in this group, without differences in other non-serious treatment-emergent adverse events.

Conclusions 1L-PEGA demonstrated superior high-quality bowel cleansing and adenoma detection compared to SPMC across a diverse range of colonoscopy indications, including varying patient ages and conditions. However, tolerability was found to be higher with SPMC.