1. Health Services Center, Ehime University , Matsuyama, Ehime 790-8577 , Japan
2. Department of Inflammatory Bowel Diseases and Therapeutics, Ehime University Graduate School of Medicine , Shitsukawa, Toon, Ehime 790-0295 , Japan
3. Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine , Shitsukawa, Toon, Ehime 790-0295 , Japan
4. Endoscopy Center, Ehime University Hospital , Shitsukawa, Toon, Ehime 791-0295 , Japan