1. Division of Gastroenterology, Department of Internal Medicine, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, 40 Sukwoo-dong, Hwaseong-si, Gyeonggi-do 445-170, Republic of Korea
2. Department of Gastroenterology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
3. Department of Gastroenterology, Seoul Soon Chun Hyang University Hospital, Soon Chun Hyang University College of Medicine, Seoul, Republic of Korea
4. Department of Gastroenterology, Kyung Hee University Hospital at Gangdong, Kyung Hee University College of Medicine, Seoul, Republic of Korea
5. Department of Gastroenterology, Yonsei University College of Medicine, Seoul, Republic of Korea
6. Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
7. Department of Gastroenterology, Bucheon Soon Chun Hyang University Hospital, Soon Chun Hyang University College of Medicine, Bucheon, Republic of Korea
8. Department of Gastroenterology, Incheon St. Mary’s Hospital, Catholic University School of Medicine, Incheon, Republic of Korea