Open Access
CC BY-NC-ND 4.0 · Endosc Int Open 2021; 09(11): E1602-E1610
DOI: 10.1055/a-1520-4596
Original article

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

Cátia Arieira
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
,
Francisca Dias de Castro
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
,
Pedro Boal Carvalho
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
,
Joana Magalhães
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
,
Sofia Xavier
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
,
Carla Sousa
1   Gastroenterology Department, Hospital da Senhora da Oliveira, Guimarães, Portugal
,
Bruno Rosa
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
,
José Cotter
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
› Author Affiliations
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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.

Supplementary material



Publication History

Received: 27 October 2020

Accepted: 10 May 2021

Article published online:
12 November 2021

© 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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