[1] Univ N Carolina, Ctr Esophageal Dis & Swallowing, Div Gastroenterol & Hepatol, Sch Med, Chapel Hill, NC USA
[2] Gastrointestinal Associates, Knoxville, TN USA
[3] Columbia Univ, Sch Med, Div Gastroenterol & Hepatol, New York, NY USA
[4] Thomas Jefferson Univ, Med Ctr, Div Gastroenterol, Philadelphia, PA 19107 USA
[5] Univ Calif Los Angeles, David Geffen Sch Med, Div Gastroenterol & Hepatol, Los Angeles, CA 90095 USA
[6] St Thomas Hosp, Div Gastroenterol, Nashville, TN USA