1. Division of Gastroenterology and Hepatology, Department of Internal Medicine Ping‐Tung Christian Hospital Pingtung Taiwan
2. Division of Gastroenterology and Hepatology, Department of Internal Medicine Kaohsiung Veterans General Hospital Kaohsiung Taiwan
3. Department of Medicine, School of Medical Sciences Universiti Sains Malaysia Kota Bahru Kelantan Malaysia
4. GI Function and Motility Unit Hospital Universiti Sains Malaysia Kota Bharu Malaysia