[1] Mayo Clin, Div Gastroenterol & Hepatol, Jacksonville, FL 32224 USA
[2] Univ Hong Kong, Dept Surg, Hong Kong, Hong Kong, Peoples R China
[3] Joseph M Smith Community Hlth Ctr, Dept Pediat, Allston, MA USA
[4] Brigham & Womens Hosp, Dept Perioperat Med & Pain Management, Boston, MA 02115 USA
[5] Vet Affairs Med Ctr, Div Gastroenterol & Hepatol, Kansas City, MO USA
[6] Univ Kansas, Med Ctr, Kansas City, MO USA
[7] Baylor Coll Med, Sect Hlth Serv Res, Houston, TX 77030 USA
[8] Baylor Coll Med, Sect Gastroenterol & Hepatol, Houston, TX 77030 USA
[9] Michael E DeBakey VA, Houston, TX USA