Kazutomo Togashi1, Kenichi Utano2, Alan Kawarai Lefor3. 1. Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakamatsu, Japan. togashik@fmu.ac.jp. 2. Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakamatsu, Japan. 3. Department of Surgery, Jichi Medical University, Shimotsuke, Japan.