1. Department of Internal Medicine, Section of Digestive Diseases, Yale School of Medicine, New Haven, Connecticut, USA
2. VA Connecticut Healthcare System, Department of Internal Medicine West Haven, Connecticut, USA
3. Division of Gastroenterology and Hepatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
4. Department of Medicine, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
5. University of Miami School of Medicine, Miami, Florida, USA
6. Bruce W Carter VA Medical Center, Miami, Florida, USA