[1] Northwestern Univ, Dept Med, Div Gastroenterol & Hepatol, Feinberg Sch Med, Chicago, IL 60611 USA
[2] Augusta Univ, Div Gastroenterol & Hepatol, Digest Hlth Ctr, Augusta, GA USA
[3] Salix Pharmaceut, Bridgewater, NJ USA
[4] Washington Univ, Div Gastroenterol, Sch Med, St Louis, MO USA
[5] Washington Univ, Dept Psychiat, Sch Med, St Louis, MO USA
[6] John Cochran Vet Affairs Med Ctr, Gastroenterol Sect, St Louis, MO USA