Toshihiro Nishizawa, Hirotoshi Ebinuma, Department of Gastroenterology and Hepatology, International University of Health and Welfare Narita Hospital, Narita 2868520, Japan
Shuntaro Yoshida, Osamu Toyoshima, Department of Gastroenterology, Toyoshima Endoscopy Clinic, Tokyo 1570066, Japan
Akira Toyoshima, Department of Colorectal Surgery, Japanese Red Cross Medical Center, Tokyo 1508935, Japan
Tomoharu Yamada, Department of Gastroenterology, The University of Tokyo, Tokyo 1138655, Japan
Yoshiki Sakaguchi, Kazuhiko Koike, Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 1138655, Japan
Taiga Irako, Department of Internal Medicine, Irako Clinic, Tokyo 1560052, Japan
Takanori Kanai, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Shinjuku-ku 1608582, Tokyo, Japan
Author contributions: Nishizawa T analyzed the data, and wrote the manuscript; Yoshida S performed colonoscopy and collected the data; Toyoshima A contributed to the data interpretation; Yamada T reviewed endoscopic images; Sakaguchi Y, Irako T, and Ebinuma H critically revised the manuscript; Kanai T and Koike K supervised the study; Toyoshima O designed the study, and analyzed the data.
Institutional review board statement: This retrospective study was approved by the Ethical Review Committee of Hattori Clinic on September 4, 2020 (approval no. S2009-U04).
Informed consent statement: Written informed consents were obtained from the participants.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Data sharing statement: No additional data are available.
: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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: Toshihiro Nishizawa, MD, PhD, Professor, Department of Gastroenterology and Hepatology, International University of Health and Welfare Narita Hospital, 852 Hatakeda, Narita, Chiba, Narita 286-8520, Japan. firstname.lastname@example.org
Received: December 31, 2020
Peer-review started: December 31, 2020
First decision: January 27, 2021
Revised: January 29, 2021
Accepted: March 18, 2021
Article in press: March 18, 2021
Published online: April 7, 2021