1. Division of Gastroenterology and Hepatology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
2. Endoscopic Center for Diagnosis and Therapy, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
3. National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan, ROC
4. Division of General Surgery, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
5. Division of Colorectal Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan, ROC