1. Gastroenterology, Toyoshima Endoscopy Clinic
2. Department of Colorectal Surgery, Japanese Red Cross Medical Center
3. Internal Medicine, Kato Medical Clinic
4. Department of Gastroenterology and Hepatology, International University of Health and Welfare, Narita Hospital
5. Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo
6. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Tokai University School of Medicine