1. Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
2. Division of Gastroenterology, Department of Internal Medicine, Hanyang University Hospital, Hanyang University College of Medicine, Seoul, Korea
3. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
4. Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea
5. Division of Gastroenterology, Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea
6. Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
7. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul, Korea
8. Division of Gastroenterology, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
9. Division of Gastroenterology, Department of Internal Medicine, Seoul Chuk Hospital, Seoul, Korea
10. Department of Internal Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea