[1] Stanford Univ, Med Ctr, Div Gastroenterol & Hepatol, Palo Alto, CA 94304 USA
[2] Univ Calif Berkeley, Berkeley, CA 94720 USA
[3] San Jose Gastroenterol, San Jose, CA USA
[4] Wong Clin, San Francisco, CA USA
[5] Chinese Hosp, San Francisco, CA USA
[6] Palo Alto Med Fdn, Gastroenterol, Mountain View, CA USA