1. Department of Gastroenterology, Faculty of Medicine, Yamagata University, Japan
2. Division of Endoscopy, Yamagata University Hospital, Japan
3. Department of Gastroenterology, National Hospital Organization, Sendai Medical Center, Japan
4. Department of Gastroenterology, Sendai City Hospital, Japan
5. Department of Gastroenterology and Neurology, Akita University Graduate School of Medicine, Japan
6. Department of Gastroenterology, South Miyagi Medical Center, Japan
7. Department of Gastroenterology, Yamagata City Hospital Saiseikan, Japan
8. Department of Gastroenterology, Tohoku Rosai Hospital, Japan
9. Department of Gastroenterology, Miyagi Cancer Center, Japan
10. Department of Gastroenterology, JR Sendai Hospital, Japan
11. Division of Gastroenterology, Tohoku University Graduate School of Medicine, Japan