1. Inflammatory Bowel Disease Center, Division of Gastroenterology, University of California San Diego, La Jolla, CA, USA
2. San Diego VA Medical Center, San Diego, CA, USA
3. Universidad Católica de Chile, Santiago, Chile
4. Hospital San Borja Arriarán, Santiago, Chile
5. Division of Gastroenterology, Medical College of Wisconsin, Milwaukee, WI, USA
6. Division of Gastroenterology, University of Virginia, Charlottesville, VI, USA
7. GI Unit, 3rd Academic Department of Internal Medicine, National and Kapodistrian University of Athens, Sotiria Hospital, Athens, Greece