1. Department of Internal Medicine, Nowon Eulji Medical Center, College of Medicine, Eulji University, Seoul 01830, Republic of Korea
2. Department of Internal Medicine, College of Medicine, Hanyang University, Seoul 04736, Republic of Korea
3. Department of Internal Medicine, Soonchunhyang University Seoul Hospital, College of Medicine, Soonchunhyang University, Seoul 04401, Republic of Korea
4. Department of Gastroenterology, School of Medicine, Ajou University, Suwon 16499, Republic of Korea
5. Department of Gastroenterology, CHA Bundang Medical Center, CHA University, Seongnam 13496, Republic of Korea