Low-volume morning-only polyethylene glycol with specially designed test meals versus standard-volume split-dose polyethylene glycol with standard diet for colonoscopy: a prospective, randomized trial

Abstract

Background/aims: Split-dose polyethylene glycol (PEG) is a standard bowel preparation regimen for colonoscopy, but the large volume is burdensome to ingest and the night dose causes sleep disturbance. This study was performed to evaluate the efficacy and tolerability of a bowel preparation protocol using low-volume morning-only PEG with specially designed low-residue test meals (LV-PEG with TM) compared to a standard-volume split-dose PEG bowel preparation with a standard diet (SV-PEG with SD).

Methods: This was a single-center, prospective, randomized, investigator-blinded, noninferiority study. The primary end point was bowel preparation quality according to the Ottawa scale. Tolerability, compliance, adverse events, sleep quality and polyp/adenoma detection were also assessed.

Results: Among 197 patients analyzed (mean age 54.6 years, 51.3% men), 97 received LV-PEG with TM and 100 received SV-PEG with SD. The Ottawa score for the total colon was 3.76 ± 2.07 in the LV-PEG with TM group and 3.67 ± 1.57 in the SV-PEG with SD group (p = 0.723; difference 0.09, 95% confidence interval -0.60 to 0.42). The compliance was high (more than 95%) in both groups (p = 0.621). PEG was easier to ingest for patients in the LV-PEG with TM group compared to the SV-PEG with SD group [visual analogue scale (VAS) for difficulty: 4.64 ± 2.46 vs. 5.97 ± 2.42, respectively; p < 0.001]. Diet instructions were also easier to comply with for patients in the LV-PEG with TM group compared to the SV-PEG with SD group (VAS for difficulty: 3.11 ± 2.25 vs. 4.00 ± 2.39, respectively; p = 0.008). Patients in the LV-PEG with TM group had a lower incidence of abdominal bloating (p = 0.012) and better sleep quality (p < 0.001). There was no difference between the groups regarding polyp and adenoma detection.

Conclusions: LV-PEG with TM and SV-PEG with SD have similar efficacy with regard to bowel preparation for colonoscopy. LV-PEG with TM provided easier PEG intake and diet compliance, less abdominal bloating and better sleep quality than SV-PEG with SD.