1. Division of Gastroenterology, Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea.
2. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
3. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Catholic University of Daegu School of Medicine, Daegu, Korea.
4. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Korea.
5. Division of Gastroenterology, Department of Internal Medicine, Fatima Hospital of Daegu, Daegu, Korea.
6. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Dongguk University School of Medicine, Gyeongju, Korea.