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