1. Department of Health Care Medicine, Kawasaki Medical School, Kurashiki, Japan
2. Department of General Internal Medicine 2, Kawasaki Medical School, Kurashiki, Japan
3. Junpukai Health Maintenance Center, Okayama, Japan
4. Junpukai Long Life Hospital, Okayama, Japan
5. Junpukai Health Maintenance Center-Kurashiki, Kurashiki, Japan
6. Department of Endoscopy and Ultrasound, Kawasaki Medical School, Kurashiki, Japan
7. Department of Practical Gastrointestinal Endoscopy, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
8. Department of Internal Medicine, Himeji Red Cross Hospital, Himeji, Japan