1. Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, and National Yang-Ming University, Taipei, Taiwan
2. Cheng Shiu University, Kaohsiung, Taiwan
3. Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
4. Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan