1. Division of Gastroenterology, Loma Linda University Medical Center, Loma Linda, CA, USA;
2. Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT, USA;
3. Digestive Diseases, VA Connecticut Healthcare System, West Haven, CT, USA;
4. Department of Gastroenterology, Sir Run Run Shaw Hospital Zhejiang University, Hangzhou, Zhejiang, China