1. Division of Gastroenterology and Hepatology, McGuire VA Medical Center and Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University, Richmond, Virginia, USA
2. School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
3. School of Medicine, George Washington University, Washington, District of Columbia, USA
4. Division of Gastroenterology, Washington DC VA Medical Center, Washington, District of Columbia, USA
5. Division of Gastroenterology, Michael E. DeBakey VA Medical Center and Baylor College of Medicine, Houston, Texas, USA
6. College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas, USA
7. Division of Gastroenterology, VA North Texas Health Care System, Dallas, Texas, USA
8. Division of Gastroenterology and Hepatology, VA North Texas Health Care System and Dell Medical School, University of Texas at Austin, Austin, Texas, USA