. 2017 Aug 31;33(4):139–145. doi: 10.3393/ac.2017.33.4.139
© 2017 The Korean Society of Coloproctology
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.