1. Gastroenterology Unit, Department of Systems Medicine, University of Rome “Tor Vergata,” Italy
2. Department of Internal Medicine and Gastroenterology, Staedtisches Klinikum Lueneburg, Lueneburg, Germany
3. Ambulanzzentrum Gastroenterologie am Klinikum Lüneburg, Lüneburg, Germany
4. Department of Clinical Sciences, L. Sacco University Hospital, Milan, Italy
5. University Hospital Erlangen, Erlangen, Germany
6. Department of Radiology and **Division of Gastroenterology, Department of Medicine, University of Calgary, Calgary, Canada
7. Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
8. Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Japan
9. Institute of Translational of Medicine, University of Birmingham, Birmingham, UK
10. Northwestern University Feinberg School of Medicine, Digestive Disease Center, Chicago, Illinois, USA