1. Division of Gastroenterology, Taichung Veterans General Hospital, Taichung 407219, Taiwan
2. School of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
3. Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung 402, Taiwan
4. Department of Otolaryngology, Taichung Veterans General Hospital, Taichung 407219, Taiwan