1. Division of Gastroenterology/Hepatology, Indiana University School of Medicine, Indianapolis, United States
2. Division of Gastroenterology, Hepatology and Motility, University of Kansas School of Medicine, Kansas City, United States
3. Department of Gastroenterology, Kansas City VA Medical Center, Kansas City, United States
4. Department of Biomedical Sciences, Humanitas University, Milan, Italy
5. Endoscopy Unit, IRCCS Humanitas Research Hospital, Rozzano, Italy