1. Inflammatory Bowel Disease Center, Division of Gastroenterology, University of California San Diego, La Jolla, CA, USA
2. Hospital San Borja Arriarán, Santiago, Chile
3. Universidad Católica de Chile, Santiago, Chile
4. VA San Diego Healthcare System, San Diego, CA, USA
5. GI Unit, 3rd Academic Department of Internal Medicine, National and Kapodistrian University of Athens, Sotiria Hospital, Athens, Greece