Shinichi Morita1, Kazuyoshi Yagi1, Shuji Terai2. 1. Department of Gastroenterology and Hepatology, Uonuma Institute of Community Medicine Niigata University Hospital, Niigata, Japan. 2. Division of Gastroenterology and Hepatology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.