1. Division of Gastroenterology, University of Florida, 1600 SW Archer Road, HD 602, Gainesville, FL 32610, USA
2. Division of Gastroenterology/Hepatology, Indiana University Medical Center, Indianapolis, IN 46202, USA
3. Rockford GE Associates, Rockford, IL 61107, USA
4. Division of Gastroenterology, Maine Medical Center, Portland, ME 04102, USA