1. Department of Gastroenterology, Juntendo University Nerima Hospital, Tokyo 177-8521, Japan
2. Department of Gastroenterology, Graduate School of Medicine, Juntendo University, Tokyo 113-8421, Japan
3. Department of Emergency Medicine, Juntendo University Nerima Hospital, Tokyo 177-8521, Japan
4. Department of Gastroenterology, Shin-Yurigaoka General Hospital, Kawasaki 215-0026, Japan