. Author manuscript; available in PMC: 2013 Jan 1.
Published in final edited form as: Clin Gastroenterol Hepatol. 2011 Jul 23;10(1):58–64.e1. doi: 10.1016/j.cgh.2011.07.005
© 2011 The American Gastroenterological Association. Published by Elsevier Inc. All rights reserved.