[1] Lenox Hill Hosp, Div Gastroenterol, New York, NY USA
[2] Johns Hopkins Med, Div Gastroenterol & Hepatol, Baltimore, MD USA
[3] Johns Hopkins Bloomberg Sch Publ Hlth, Div Summer Internship Program, Baltimore, MD USA
[4] Johns Hopkins Univ, Sch Med, Dept Med, Baltimore, MD 21205 USA