1. Department of Internal Medicine, Hallym University Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Korea
2. Department of Gastroenterology, CHA Bundang Medical Center, CHA University College of Medicine, Seongnam, Korea
3. Division of Gastroenterology, Department of Internal Medicine, Tokat Gaziosmanpasa University School of Medicine, Tokat, Turkey