1. Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea.
3. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
4. Institute for Digestive Research, Soonchunhyang University College of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
6. Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
7. Department of Internal Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea.
8. Department of Gastroenterology, University of Ulsan College of Medicine, Seoul, Korea.
9. Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea.
10. Department of Internal Medicine and Digestive Disease Research Institute, Wonkwang University School of Medicine, Iksan, Korea.