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Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 7, 2015; 21(21): 6451-6459
Published online Jun 7, 2015. doi: 10.3748/wjg.v21.i21.6451
Diagnostic and therapeutic applications of water-immersion colonoscopy
Shinya Sugimoto, Takeshi Mizukami
Shinya Sugimoto, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
Takeshi Mizukami, Endoscopy Center, NHO Kurihama Medical and Addiction Center, Yokosuka, Kanagawa 239-0841, Japan
Author contributions: Sugimoto S drafted the manuscript; Mizukami T contributed to critical revision of the manuscript for important intellectual content; Mizukami T contributed to supervision; all authors approved the final manuscript.
Conflict-of-interest: The authors declare no conflict of interest.
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/
Correspondence to: Shinya Sugimoto, MD, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. sugimoto-kei@umin.ac.jp
Telephone: +81-3-33531211 Fax: +81-3-33536247
Received: January 13, 2015
Peer-review started: January 14, 2015
First decision: March 10, 2015
Revised: March 15, 2015
Accepted: April 28, 2015
Article in press: April 28, 2015
Published online: June 7, 2015
Abstract

Colonoscopy techniques combining or replacing air insufflation with water infusion are becoming increasingly popular. They were originally designed to reduce colonic spasms, facilitate cecal intubation, and lower patient discomfort and the need for sedation. These maneuvers straighten the rectosigmoid colon and enable the colonoscope to be inserted deeply without causing looping of the colon. Water-immersion colonoscopy minimizes colonic distension and improves visibility by introducing a small amount of water. In addition, since pain during colonoscopy indicates risk of bowel perforation and sedation masks this important warning, this method has the potential to be the favored insertion technique because it promotes patient safety without sedation. Recently, this water-immersion method has not only been used for colonoscope insertion, but has also been applied to therapy for sigmoid volvulus, removal of lesions, lower gastrointestinal bleeding, and therapeutic diagnosis of abnormal bowel morphology and irritable bowel syndrome. Although a larger sample size and prospective head-to-head-designed studies will be needed, this review focuses on the usefulness of water-immersion colonoscopy for diagnostic and therapeutic applications.

Keywords: Colonoscopy, Water immersion, Water exchange, Underwater, Unsedated, Sigmoid volvulus, Detorsion, Polypectomy, Gastrointestinal bleeding, Irritable bowel syndrome

Core tip: Water-immersion colonoscopy minimizes colonic distension, reducing patient discomfort and the need for sedation. Due to these characteristic advantages, this method has been applied to treatment in diverse ways, not just as an insertion technique during colonoscopy. Its ease and safety are favorable for detorsion for sigmoid volvulus and treatment of lower gastrointestinal bleeding in the early postoperative period. Underwater endoscopic mucosal resection increases the proportion of completely resected lesions, and reduces recurrence, posttreatment bleeding, and perforation. Water-immersion colonoscopy is also useful for estimating the colon morphology based on changes in the water surface and the rotated direction of the colon.