1. Division of Gastroenterology and Hepatology, Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan;
2. School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan;
3. Department of Post-Baccalaureate Medicine, National Sun Yat-sen University, Kaohsiung, Taiwan;
4. Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan;
5. Endoscopy Center for Diagnosis and Treatment, Taipei Veterans General Hospital, Taipei, Taiwan.