[1] David Grant Med Ctr, Dept Gastroenterol Hepatol & Motil, Fairfield, CA 94533 USA
[2] Univ Calif Davis, Clin Fac, Dept Med, USUHS, Davis, CA USA
[3] Univ Mississippi, Dept Med, Baptist GI, Med Ctr, Jackson, MS USA
[4] Univ Washington, Dept Med, Div Gastroenterol, Sch Med, Seattle, WA USA