Clinical Trials Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jan 6, 2019; 7(1): 39-48
Published online Jan 6, 2019. doi: 10.12998/wjcc.v7.i1.39
Efficacy of 0.5-L vs 1-L polyethylene glycol containing ascorbic acid as additional colon cleansing methods for inadequate bowel preparation as expected by last stool examination before colonoscopy
Joon Hyun Cho, Eun Joo Goo, Kyeong Ok Kim, Si Hyung Lee, Byung Ik Jang, Tae Nyeun Kim
Joon Hyun Cho, Eun Joo Goo, Kyeong Ok Kim, Si Hyung Lee, Byung Ik Jang, Tae Nyeun Kim, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Yeungnam University College of Medicine, Daegu 42415, South Korea
Author contributions: Kim TN and Kim KO designed the research; Kim TN, Jang BI, Lee SH, Kim KO, and Goo EJ performed the research; Goo EJ and Cho JH analyzed the data; Kim TN and Cho JH wrote the paper; Kim TN and Cho JH revised the manuscript.
Institutional review board statement: The study was performed in accordance with the Helsinki Declaration and the protocol and informed consent form used were approved beforehand by the Institutional Review Board of Yeungnam University Hospital (IRB No. 2016-03-019).
Informed consent statement: All patients provided written informed consent.
Conflict-of-interest statement: The authors declare no conflicts of interest regarding this manuscript.
Data sharing statement: There are no additional data available for this study.
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: Tae Nyeun Kim, MD, PhD, Professor, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Yeungnam University College of Medicine, 170 Hyeonchung-ro, Nam-gu, Daegu 42415, South Korea. tnkim@yu.ac.kr
Telephone: +82-53-6203842 Fax: +82-53-6548386
Received: September 21, 2018
Peer-review started: September 21, 2018
First decision: November 2, 2018
Revised: November 19, 2018
Accepted: November 23, 2018
Article in press: November 24, 2018
Published online: January 6, 2019
ARTICLE HIGHLIGHTS
Research background

Inadequate bowel preparation negatively affects the efficacy and quality of colonoscopy. However, no consensus has been reached regarding optimal salvage methods in patients suspected of having inadequate bowel preparation. Some reports have been issued on the effectiveness of colonoscopic enema in this context, but the most ideal and reasonable rescue option involves early suspicion and identification of patients with inadequate preparation before sedation, additional oral ingestion of a suitable preparation formulation, and same-day colonoscopy.

Research motivation

Many studies have compared the efficacy of bowel cleansing methods or sought to identify the risk factors of inadequate bowel preparation. However, few have examined the efficacy of additional oral preparations when inadequate bowel preparation is suspected. Therefore, we compared the bowel cleansing efficacy of 0.5-L polyethylene glycol containing ascorbic acid (PEG + Asc) and 1-L PEG + Asc as rescue options before colonoscopy.

Research objectives

The objective of this investigation was to compare the efficacy of 0.5-L and 1-L PEG + Asc as additional bowel cleansing methods for inadequate bowel preparation as expected by last stool examination before colonoscopy.

Research methods

Over a 10-mo period, 90 patients expected to have inadequate bowel preparation before screening colonoscopy were included in this prospective, investigator–blinded, randomized study. Patients with last rectal effluents described as turbid liquid, particulate liquid, or liquid with small amounts of feces were equally randomized to a 0.5-L PEG + Asc group or a 1-L PEG + Asc group.

Research results

No significant intergroup differences were found between the two groups with respect to adequate bowel preparation (as assessed by Aronchick bowel preparation scale and Boston bowel preparation scale). Polyp detection rates and adenoma detection rates were similar in the two groups, and cecal intubation and withdrawal times were not significantly different. However, mean patient satisfaction score was significantly higher in the 0.5-L group.

Research conclusions

Of the study subjects, 84.4% showed excellent or good preparation as assessed by BBPS during colonoscopy. The efficacy of the additional 0.5-L PEG + Asc regimen was not inferior to the additional 1-L PEG + Asc regimen as a salvage option for inadequate bowel preparation as expected by last stool before colonoscopy. Furthermore, patient satisfaction was significantly higher in the 0.5-L group. Thus, the 0.5-L PEG + Asc regimen appears to be sufficient when inadequate bowel preparation is expected before initiating colonoscopy, based on considerations of bowel cleansing efficacy and patient satisfaction.

Research perspectives

This study is the first prospective randomized trial to compare the effects of two additional PEG + Asc doses in patients suspected to be poorly prepared for colonoscopy. If less uncomfortable and low-volume oral preparations are developed in the near future, research on oral rescue preparation for inadequate bowel preparation before colonoscopy will become more active.