1. Division of Endoscopy and Ultrasonography, Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School, Kurashiki, Japan
2. Department of General Internal Medicine 2, Kawasaki Medical School General Medical Center, Okayama, Japan
3. Division of Gastroenterology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Japan
4. Department of Health Care Medicine, Kawasaki Medical School, Kurashiki, Japan
5. Department of Health Care Medicine, Kawasaki Medical School General Medical Center, Okayama, Japan