[1] Harborview Med Ctr, Div Gastroenterol, Dept Med, Seattle, WA 98104 USA
[2] Univ Washington, Sch Med, Seattle, WA USA
[3] Harvard Univ, Sch Publ Hlth, Dept Nutr, Boston, MA 02115 USA
[4] Harvard Univ, Sch Publ Hlth, Dept Epidemiol, Boston, MA 02115 USA
[5] Harvard Univ, Sch Med, Boston, MA 02115 USA
[6] Brigham & Womens Hosp, Dept Med, Div Gastroenterol, Boston, MA 02115 USA
[7] Brigham & Womens Hosp, Dept Med, Channing Lab, Boston, MA 02115 USA
[8] Dana Farber Canc Inst, Div Populat Sci, Boston, MA 02115 USA
[9] Wyeth Consumer Healthcare Inc, Mississauga, ON, Canada