[1] Med Univ South Carolina, Div Gastroenterol & Hepatol, Charleston, SC 29425 USA
[2] Mayo Clin, Div Gastroenterol & Hepatol, Scottsdale, AZ USA
[3] Wake Forest Sch Med, Sect Gastroenterol & Hepatol, Winston Salem, NC USA
[4] Indiana Univ Sch Med, Div Gastroenterol & Hepatol, Indianapolis, IN USA
[5] Univ Calif San Diego, Div Gastroenterol & Digest Hlth, San Diego, CA USA
[6] Univ N Carolina, Div Gastroenterol & Hepatol, Chapel Hill, NC USA