1. Department of Internal Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Gangwon-do, Korea
2. Division of Gastroenterology, Department of Internal Medicine, Inje University Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea
3. Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea
4. Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
5. Department of Internal Medicine, Seoul St. Mary’s Hospital, The Catholic University of Korea, Seoul, Korea
6. Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
7. Division of Gastroenterology, Department of Internal Medicine, Good Gangan Hospital, Busan, Korea
8. Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea