HauserSpread 8/5/08 12:25 PM Page 1 About the book… Mayo Clinic Written by an experienced and dedicated team of Mayo Clinic gastroenterologists and hepatologists, this newly expanded and updated Third Edition of the best-selling Mayo Clinic Hauser Gastroenterology and Hepatology Board Review is the go-to comprehensive resource for a Gastroenterology and Hepatology complete scope of essential knowledge in all areas of gastroenterology and hepatology and in the related areas of pathology, endoscopy, nutrition, and radiology. Review Clinic Gastroenterology and Hepatology Mayo Board Board Review The new edition is an easy-to-use, case-based text expertly designed for those preparing to take the gastroenterology board examination and for gastroenterologists in need of recertification. Third Edition Medical students and residents in the areas of internal medicine and gastroenterology, gastroen- terology fellows, and physicians seeking a practical and comprehensive review of gastroenterology and hepatology will also benefit from this stand-alone guide. New features in the Third Edition include: • Several new multiple-choice questions and answers addressing the growing areas of concern in gastroenterology and hepatology • 12 substantially updated and revised chapters by new authors who provide fresh, cutting- edge perspectives • A new chapter on drug-induced liver injury • Increased emphasis on case-based learning, which is critical to superior diagnostic and thera- peutic approaches to patient care • The addition of more than 100 high-quality color photographs • Content that is organized by subspecialty areas, including esophageal, gastroduodenal, and colonic disorders, small-bowel disease and nutrition, pancreaticobiliary and liver diseases, and other miscellaneous disorders • An abundance of additional new material appropriate for the board review and practice About the editors... STEPHEN C. HAUSER, MD, is Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota; Assistant Professor of Medicine, College of Medicine, Mayo Clinic Editor DARRELL S. PARDI, MD, is Consultant, Division of Gastroenterology and Hepatology, Stephen C. Hauser, MD Mayo Clinic, Rochester, Minnesota; Associate Professor of Co-Editors Medicine, College of Medicine, Mayo Clinic Third Edition Darrell S. Pardi, MD JOHN J. POTERUCHA, MD, is Consultant, Division of John J. Poterucha, MD Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota; Associate Professor of Medicine, College of Medicine, Mayo Clinic MAYO CLINIC SCIENTIFIC PRESS Mayo Clinic Gastroenterology and Hepatology Board Review Third Edition Mayo Clinic Gastroenterology and Hepatology Board Review Third Edition Editor Stephen C. Hauser, MD Co-Editors Darrell S. Pardi, MD John J. Poterucha, MD MAYO CLINIC SCIENTIFIC PRESS AND INFORMA HEALTHCARE USA, INC The triple-shield Mayo logo and the words MAYO, MAYO CLINIC, and MAYO CLINIC SCIENTIFIC PRESS are marks of Mayo Foundation for Medical Education and Research. ©2008 Mayo Foundation for Medical Education and Research. All rights reserved. This book is protected by copyright. No part of it may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means—electronic, mechanical, photocopying, recording, or otherwise—without the prior written consent of the copyright holder, except for brief quotations embodied in critical articles and reviews. Inquiries should be addressed to Scientific Publications, Plummer 10, Mayo Clinic, 200 First Street SW, Rochester, MN 55905. For order inquiries, contact Informa Healthcare, Kentucky Distribution Center, 7625 Empire Drive, Florence, KY 41042 USA. E-mail: [email protected]; Web site: www.informahealthcare.com. www.taylorandfrancis.com Library of Congress Cataloging-in-Publication Data Mayo Clinic gastroenterology and hepatology board review/edited by Stephen C. Hauser, Darrell S. Pardi, John J. Poterucha. — 3rd ed. p. ; cm. Includes bibliographical references and index. ISBN-13: 978-1-4200-9223-3 (pbk. : alk. paper) ISBN-10; 1-4200-9223-5 (pbk. : alk. paper) 1. Gastroenterology—Examinations, questions, etc. 2. Gastrointestinal system—Examinations, questions, etc. 3. Liver—Diseases—Examinations, questions, etc. I. Hauser, Stephen C. II. Pardi, Darrell S. III. Poterucha, John J. IV. Mayo Clinic. V. Title: Gastroenterology and hepatology board review. [DNLM: 1. Gastrointestinal Diseases—Examination Questions. WI 18.2 M473 2008] RC801.M33 2008 616.3’30076—dc22 Printed in Canada 2008024970 Care has been taken to confirm the accuracy of the information presented and to describe generally accepted practices. However, the authors, editors, and publisher are not responsible for errors or omis- sions or for any consequences from application of the information in this book and make no warranty, express or implied, with respect to the contents of the publication. This book should not be relied on apart from the advice of a qualified health care provider. The authors, editors, and publisher have exerted efforts to ensure that drug selection and dosage set forth in this text are in accordance with current recommendations and practice at the time of pub- lication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, readers are urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new or infrequently employed drug. Some drugs and medical devices presented in this publication have Food and Drug Administration (FDA) clearance for limited use in restricted research settings. It is the responsibility of the health care providers to ascertain the FDA status of each drug or device planned for use in their clinical practice. LIST OF CONTRIBUTORS Jeffrey A. Alexander, MD Albert J. Czaja, MD Consultant, Division of Gastroenterology and Emeritus Staff Consultant, Division of Hepatology, Mayo Clinic, Rochester, Minnesota; Gastroenterology and Hepatology, Mayo Clinic, Assistant Professor of Medicine, College of Rochester, Minnesota; Emeritus Staff Professor Medicine, Mayo Clinic of Medicine, College of Medicine, Mayo Clinic Paul Angulo, MD Dawn L. Francis, MD, MHS Consultant, Division of Gastroenterology and Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota; Hepatology, Mayo Clinic, Rochester, Minnesota; Associate Professor of Medicine, College of Assistant Professor of Medicine, College of Medicine, Mayo Clinic Medicine, Mayo Clinic Amindra S. Arora, MBBChir Stephen C. Hauser, MD Consultant, Division of Gastroenterology and Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota; Hepatology, Mayo Clinic, Rochester, Minnesota; Assistant Professor of Medicine, College of Assistant Professor of Medicine, College of Medicine, Mayo Clinic Medicine, Mayo Clinic Todd H. Baron, Sr., MD J. Eileen Hay, MB,ChB Consultant, Division of Gastroenterology and Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota; Hepatology, Mayo Clinic, Rochester, Minnesota; Professor of Medicine, College of Medicine, Professor of Medicine, College of Medicine, Mayo Clinic Mayo Clinic Adil E. Bharucha, MBBS, MD Patrick S. Kamath, MD Consultant, Division of Gastroenterology and Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota; Hepatology, Mayo Clinic, Rochester, Minnesota; Professor of Medicine, College of Medicine, Professor of Medicine, College of Medicine, Mayo Clinic Mayo Clinic Lisa A. Boardman, MD Paul J. Limburg, MD, MPH Consultant, Division of Gastroenterology and Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota; Hepatology, Mayo Clinic, Rochester, Minnesota; Assistant Professor of Medicine, College of Associate Professor of Medicine, College of Medicine, Mayo Clinic Medicine, Mayo Clinic Michael Camilleri, MD Keith D. Lindor, MD Consultant, Division of Gastroenterology and Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota; Hepatology, Mayo Clinic, Rochester, Minnesota; Professor of Medicine and of Physiology, College Professor of Medicine, College of Medicine, of Medicine, Mayo Clinic Mayo Clinic Suresh T. Chari, MD G. Richard Locke III, MD Consultant, Division of Gastroenterology and Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota; Hepatology, Mayo Clinic, Rochester, Minnesota; Professor of Medicine, College of Medicine, Professor of Medicine, College of Medicine, Mayo Clinic Mayo Clinic ix DEDICATION To the many persons who have taught, encouraged, and inspired us. v PREFACE astroenterology and hepatology encompass a large assortment of organs with diverse Gstructure and function that potentially are afflicted by a multiplicity of disease processes. We have designed the revised edition of the Mayo Clinic Gastroenterology and Hepatology Board Review book and course to assist physicians-in-training who are preparing for the gastroenterology board examination and the growing number of gas- troenterologists who are awaiting recertification. The book is not intended to replace the more encyclopedic textbooks of gastroenterology, hepatology, pathology, endoscopy, nutrition, and radiology now available. Nor is it intended to serve as an “update” to physicians who are looking