[1] Northwestern Univ, Feinberg Sch Med, Div Gastroenterol, 676 North St Clair,Suite 1400, Chicago, IL 60611 USA
[2] Univ N Carolina, Sch Med, Ctr Esophageal Dis & Swallowing, Div Gastroenterol & Hepatol, Chapel Hill, NC USA
[3] Baylor Univ, Med Ctr Dallas, Ctr Esophageal Dis, Div Gastroenterol, Dallas, TX USA
[4] Baylor Scott & White Res Inst, Ctr Esophageal Res, Dallas, TX USA
[5] Univ Colorado, Sch Med, Div Gastroenterol, Denver, CO 80202 USA