1. Department of Gastroenterology and Hepatology, University of Kansas Medical Center, Kansas City, KS, USA
2. Department of Gastroenterology, Kansas City VA Medical Center, Kansas City, KS, USA
3. Division of Gastroenterology, University of Nevada, Las Vegas, NV, USA
4. Division of Gastroenterology, Humanitas Research Hospital & Humanitas University, Milan, Italy
5. Nuovo Regina Margherita Hospital, Digestive Endoscopy Unit, Rome, Italy
6. Department of Medical and Surgical Sciences, S. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy