1. Department of Research and Development, Detroit John D. Dingle VAMC, Detroit, MI 48201, USA
2. Gastroenterology Section, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
3. The Oregon Clinic-Gastroenterology South, Oregon City, OR 97045, USA
4. Division of Gastroenterology, Hepatology and Nutrition, Gainesville VAMC, University of Florida, Gainesville, FL 62308, USA
5. Capital Health Gastroenterology Specialists, Pennington, NJ 08324, USA