Bowel cleansing efficacy for colonoscopy: prospective, randomized comparative study of same-day dosing with 1-L and 2-L PEG + ascorbate

Cátia Arieira; Francisca Dias de Castro; Pedro Boal Carvalho; Joana Magalhães; Sofia Xavier; Carla Sousa; Bruno Rosa; José Cotter

doi:10.1055/a-1520-4596

Bowel cleansing efficacy for colonoscopy: prospective, randomized comparative study of same-day dosing with 1-L and 2-L PEG + ascorbate

Endosc Int Open. 2021 Nov 12;9(11):E1602-E1610. doi: 10.1055/a-1520-4596. eCollection 2021 Nov.

Authors

Cátia Arieira^{1

2

3}, Francisca Dias de Castro^{1

2

3}, Pedro Boal Carvalho^{1

2

3}, Joana Magalhães^{1

2

3}, Sofia Xavier^{1

2

3}, Carla Sousa¹, Bruno Rosa^{1

2

3}, José Cotter^{1

2

3}

Affiliations

¹ Gastroenterology Department, Hospital da Senhora da Oliveira, Guimarães, Portugal.
² Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga/Guimarães, Portugal.
³ Life and Health Sciences Research Institute (ICVS)/3B's Research Group, PT Government Associate Laboratory, Braga/Guimarães, Portugal.

Abstract

Background and study aims Polyethylene glycol (PEG) bowel preparations are effective but associated with high ingestion volume. In this study, 1-L PEG and 2-L PEG preparations were compared in a randomized, colonoscopist-blinded, single-center trial. Patients and methods Patients were aged > 18 years, required colonoscopy, and provided informed consent. Randomization was 1:1 to 1-L PEG or 2-L PEG, based on hospital identification number (odd or even). Preparations were administered using same-day dosing adjusted for colonoscopy start time. The primary endpoint was successful bowel preparation on the Boston Bowel Preparation Scale (BBPS) (no segment scored < 2). Results A total of 852 patients were randomized. In the intention-to-treat (ITT) population, significantly more patients had diabetes in the 2-L PEG arm, resulting in the creation of the modified-ITT population (mITT) that excluded diabetic patients to correct the imbalance (1-L PEG, n = 239; 2-L PEG, n = 238). In the mITT, there was no significant difference in successful cleansing between 1-L PEG and 2-L PEG (88.3 % vs. 82.4 %; P = 0.067). Excellent cleansing (BBPS 7-9; no segment < 2) was significantly improved with 1-L PEG (60.7 % vs. 50.4 %; P < 0.024), as were mean scores in the right and left colon (right: 2.47 vs. 2.30; P < 0.008; left: 2.55 vs. 2.39; P = 0.008). Adverse events were mild to moderate in intensity and none resulted in discontinuation. Rates of nausea and vomiting were significantly higher with 1-L PEG, but that did not affect successful cleansing. Conclusions The lower-volume 1-L PEG was associated with higher levels of excellent bowel cleansing and greater mean segmental scores on the BBPS than 2-L PEG.

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