1. Department of Gastroenterology and Neurology, Kagawa Medical University School of Medicine, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
2. Department of Gastroenterological Surgery, Kagawa Medical University School of Medicine, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan