Randomized Controlled Trial
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Feb 26, 2019; 7(4): 452-465
Published online Feb 26, 2019. doi: 10.12998/wjcc.v7.i4.452
Efficacy of 1.2 L polyethylene glycol plus ascorbic acid for bowel preparations
Hiroyuki Tamaki, Teruyo Noda, Masahiro Morita, Akina Omura, Atsushi Kubo, Chikara Ogawa, Toshihiro Matsunaka, Mitsushige Shibatoge
Hiroyuki Tamaki, Teruyo Noda, Masahiro Morita, Akina Omura, Atsushi Kubo, Chikara Ogawa, Toshihiro Matsunaka, Mitsushige Shibatoge, Department of Gastroenterology, Takamatsu Red Cross Hospital, Takamatsu, Kagawa 760-0017, Japan
Author contributions: Tamaki H was fully involved in the patient management, acquisition and interpretation of data, statistics, drafting, and preparation of final manuscript version; Shibatoge M was contributed to make the conception, study design, interpretation of data and critical review of the final manuscript version; all authors contributed to correction of the clinical data.
Institutional review board statement: The protocol of this study was approved by the Investigational Review Board of Takamatsu Red Cross Hospital.
Clinical trial registration: This trial is registered at https://www.umin.ac.jp/ctr/index-j.htm. The registration identification number is UMIN000020904.
Informed consent statement: All patients provided written informed consent for their participation.
Conflict-of-interest statement: The authors of this manuscript have no conflicts of interest to disclose.
Data sharing statement: All authors agree that if this manuscript is finally accepted for publication, the Copyright License Agreement will become effective immediately.
CONSORT 2010 statement: The authors have read the CONSORT 2010 Statement, and the manuscript was prepared and revised according to the CONSORT 2010 Statement.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Mitsushige Shibatoge, MD, PhD, Department of Gastroenterology, Takamatsu Red Cross Hospital, 4-1-3 Ban-cho, Takamatsu, Kagawa 760-0017 Japan. shibatoge-mitsusige@takamatsu.jrc.or.jp
Telephone: +81-87-8317101 Fax: +81-87-8347809
Received: October 25, 2018
Peer-review started: October 26, 2018
First decision: November 29, 2018
Revised: December 24, 2018
Accepted: January 23, 2019
Article in press: January 24, 2019
Published online: February 26, 2019
ARTICLE HIGHLIGHTS
Research background

Inadequate bowel preparation is a serious matter on screening colonoscopy because it may result in a higher adenoma miss rate, prolonged procedure time, lower colonoscopy completion rate, and increased cost because of the need for an earlier repeat examination.

Research motivation

Low-volume regimens that combine polyethylene glycol (PEG) and osmotic or stimulant agents are developed to improve acceptability. Although several reports showed that the combination of PEG plus ascorbic acid (PEG-ASC) solution lower than 2.0 L and laxative agents could be alternative to traditional preparation regimen, the cleansing protocols have not been fully investigated.

Research objectives

We aimed to evaluate the cleansing efficacy of 1.2 L PEG-ASC comparing with 2.0 L PEG electrolyte (PEG-ELS) combined with sennoside as bowel preparations for afternoon colonoscopy.

Research methods

A randomized, single-blinded, open-label, single-center, non-inferiority study was conducted. In total, 312 Japanese adult patients (aged > 18 years) who underwent colonoscopy were enrolled. Patients were randomly allocated to bowel lavage with either 1.2 L of PEG-ASC solution with at least 0.6 L of an additional clear fluid (1.2L PEG-ASC group) or 2.0 L of PEG-ELS (PEG-ELS group). Then, 48 mg of sennoside was administered at bedtime on the day before colonoscopy, and the designated drug solution was administered at the hospital on the day of colonoscopy. Bowel cleansing was evaluated using the Boston Bowel Preparation Scale (BBPS). The volume of fluid intake and required time for bowel preparation were evaluated. Furthermore, compliance, patient tolerance, and overall acceptability were evaluated using a patient questionnaire, which was assessed using a visual analog scale.

Research results

In total, 291 patients (1.2 L PEG-ASC group, 148; PEG-ELS group, 143) completed the study. There was no significant difference in successful cleansing, defined as a BBPS score ≥ 2 in each segment, between the two groups (1.2 L PEG-ASC group, 91.9%; PEG-ELS group, 90.2%; 95%CI: -0.03-0.09). The required time for bowel preparation was significantly shorter (164.95 min ± 68.95 min vs 202.16 min ± 68.69 min, P < 0.001) and the total fluid intake volume was significantly lower (2.23 L ± 0.55 L vs 2.47 L ± 0.56 L, P < 0.001) in the 1.2 L PEG-ASC group than in the PEG-ELS group. Palatability, acceptability of the volume of solution, and overall acceptability evaluated using a patient questionnaire, which was assessed by the visual analog scale, were significantly better in the 1.2 L PEG-ASC group than in the PEG-ELS group (7.70 cm ± 2.57 cm vs 5.80 cm ± 3.24 cm, P < 0.001). No severe adverse event was observed in each group.

Research conclusions

This study demonstrated that 1.2 L of PEG-ASC and 2.0 L of PEG-ELS are clinically equivalent with respect to cleansing efficacy, including ADR. Furthermore, the 1.2 L PEG-ASC regimen was superior to the 2.0 L PEG-ELS regimen in terms of the required time for bowel preparation, palatability, and acceptability. These results support that combination of 1.2 L PEG-ASC solution and sennoside with prior low-residue diet is a suitable alternative to the standard bowel preparation with PEG-ELS in outpatients for afternoon colonoscopy.

Research perspectives

We have to take the difference between the races and the region into consideration when we discuss the efficacy of bowel cleansing regimens. They can vary in effectiveness depending on the racial or regional groups because body dimensions, diet habits, and bowel transit time, etc., vary among population and are considered to affect the reactivity for cleansing agents. Although the efficacy of the combination of PEG-ASC lower than 2 L plus bisacodyl or sennoside was currently evaluated only in East Asia, they are thought to be effective in the population who are successfully treated with 2 L PEG-ELS plus laxative. In this point of view, further studies in various races and regions are required to confirm the efficacy of PEG-ASC lower than 2.0 L plus laxative.