1. Division of Gastroenterology & Hepatology, Minneapolis VA Medical Center, University of Minnesota, Minneapolis, Minnesota, USA;
2. Division of Gastroenterology and Hepatology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA;
3. Medical College of Wisconsin, Milwaukee, Wisconsin, USA;
4. GI Associates, Racine, Kenosha, and Milwaukee, Wisconsin, USA;
5. Division of Gastroenterology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA;
6. Division of Gastroenterology, Kaiser Permanente, Seattle, Washington, USA;
7. Division of Gastroenterology and Hepatology, Department of Veterans Affairs Medical Center, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA;
8. University of Connecticut School of Medicine, Farmington, Connecticut, USA;
9. Section of Gastroenterology, Wake Forest University School of Medicine, Winston Salem, North Carolina, USA.