Chi-Liang Cheng1, Nai-Jen Liu2, Ming-Chin Yu3. 1. Department of Gastroenterology, Zhongli Evergreen Hospital, Taoyuan, Taiwan. 2. Division of Digestive Therapeutic Endoscopy, Department of Medicine, Chang Gung Hospital and Chang Gung University, Taoyuan, Taiwan. 3. Division of General Surgery, Department of Surgery, Chang Gung Hospital and Chang Gung University, Taoyuan, Taiwan.