1. Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Japan
2. Department of Gastroenterology, Osaka Rosai Hospital, Sakai, Japan
3. Department of Gastroenterology, Kansai Rosai Hospital, Amagasaki, Japan
4. Department of Gastroenterology, Osaka National Hospital, National Hospital Organization, Osaka, Japan
5. Department of Gastroenterology, Sakai City Hospital, Sakai, Japan
6. Department of Gastroenterology, Toyonaka Municipal Hospital, Toyonaka, Japan
7. Department of Gastroenterology, Sumitomo Hospital, Osaka, Japan
8. Department of Gastroenterology, Osaka Police Hospital, Osaka, Japan
9. Department of Gastroenterology, Itami City Hospital, Itami, Japan
10. Department of Gastroenterology, Minoh City Hospital, Minoh, Japan
11. Department of Gastroenterology, Osaka Kosei-Nenkin Hospital, Osaka, Japan
12. Department of Clinical Epidermiology, Osaka University Graduate School of Medicine, Suita, Japan