1. Section of Colon and Rectal Surgery, Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
2. IBD Study Group, Korean Society of Coloproctology, Korea.
3. Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
4. Department of Surgery, Sungkyunkwan University School of Medicine, Seoul, Korea.
5. Department of Surgery, Kyungpook National University School of Medicine, Daegu, Korea.
6. Department of Surgery, Kyung Hee University School of Medicine, Seoul, Korea.
7. Department of Surgery, Hansol Hospital, Seoul, Korea.
8. Section of Colon and Rectal Surgery, Department of Surgery, University of Ulsan, College of Medicine and Asan Medical Center, Seoul, Korea.