1. Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon 14584, Republic of Korea
2. Department of Internal Medicine, Soonchunhyang University School of Medicine, Cheonan 31151, Republic of Korea
3. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon 14584, Republic of Korea