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Gastroenterology and Hepatology Committee Editor-in-Chief Sonia S. Kupfer, MD, Section Editor Davoren Chick, MD, FACP Associate Professor of Medicine Senior Vice President, Medical Education Section of Gastroenterology, Hepatology, and Nutrition American College of Physicians Department of Medicine Philadelphia, Pennsylvania University of Chicago Chicago, Illinois Senior Deputy Editor Rotonya M. Carr, MD Patrick C. Alguire, MD, FACP Associate Professor of Medicine American College of Physicians Director, Liver Metabolism and Fatty Liver Program Philadelphia, Pennsylvania Division of Gastroenterology University of Pennsylvania Deputy Editor Philadelphia, Pennsylvania Robert L. Trowbridge, Jr., MD, FACP Vani J.A. Konda, MD Department of Medicine Clinical Director, Center for Esophageal Diseases Maine Medical Center Baylor University Medical Center Portland, Maine Dallas, Texas Tufts University School of Medicine Benjamin Lebwohl, MD, MS Boston, Massachusetts

Committee Editor-in-Chief Sonia S. Kupfer, MD, Section Editor Davoren Chick, MD, FACP Associate Professor of Medicine Senior Vice President, Medical Education Section of Gastroenterology, Hepatology, and Nutrition American College of Physicians Department of Medicine Philadelphia, Pennsylvania University of Chicago Chicago, Illinois Senior Deputy Editor Rotonya M. Carr, MD Patrick C. Alguire, MD, FACP Associate Professor of Medicine American College of Physicians Director, Liver Metabolism and Fatty Liver Program Philadelphia, Pennsylvania Division of Gastroenterology University of Pennsylvania Deputy Editor Philadelphia, Pennsylvania Robert L. Trowbridge, Jr., MD, FACP Vani J.A. Konda, MD Department of Medicine Clinical Director, Center for Esophageal Diseases Maine Medical Center Baylor University Medical Center Portland, Maine Dallas, Texas Tufts University School of Medicine Benjamin Lebwohl, MD, MS Boston, Massachusetts Director of Clinical Research The Celiac Disease Center at Columbia University Gastroenterology and Hepatology Director of Quality Improvement Reviewers Division of Digestive and Liver Diseases Gyorgy Baffy, MD, PhD, FACP Columbia University Department of Medicine Linda A. Feagins, MD New York, New York Kathleen M Finn, MD, M.Phil, FACP Aimee Lucas, MD, MS Grigoriy E. Gurvits, MD, FACP Associate Professor Sunanda Kane, MD, MSPH, FACP Henry D. Janowitz Division of Gastroenterology Alvaro Martinez-Camacho, MD, FACP Icahn School of Medicine at Mount Sinai Kenneth K. Mills-Robertson, MD New York, New York Gordon Ohning, MD, PhD, FACP Peter M. Rosenberg, MD, FACP Roman Perri, MD John Erikson L. Yap, MD, FACP Assistant Professor of Medicine Division of Gastroenterology, Hepatology, and Nutrition Vanderbilt University Medical Center Hospital Medicine Gastroenterology and Nashville, Tennessee Hepatology Reviewers Richard J. Saad, MD, MS Adegboyega Olayode, MD, MPH, FACP

Director of Clinical Research The Celiac Disease Center at Columbia University Gastroenterology and Hepatology Director of Quality Improvement Reviewers Division of Digestive and Liver Diseases Gyorgy Baffy, MD, PhD, FACP Columbia University Department of Medicine Linda A. Feagins, MD New York, New York Kathleen M Finn, MD, M.Phil, FACP Aimee Lucas, MD, MS Grigoriy E. Gurvits, MD, FACP Associate Professor Sunanda Kane, MD, MSPH, FACP Henry D. Janowitz Division of Gastroenterology Alvaro Martinez-Camacho, MD, FACP Icahn School of Medicine at Mount Sinai Kenneth K. Mills-Robertson, MD New York, New York Gordon Ohning, MD, PhD, FACP Peter M. Rosenberg, MD, FACP Roman Perri, MD John Erikson L. Yap, MD, FACP Assistant Professor of Medicine Division of Gastroenterology, Hepatology, and Nutrition Vanderbilt University Medical Center Hospital Medicine Gastroenterology and Nashville, Tennessee Hepatology Reviewers Richard J. Saad, MD, MS Adegboyega Olayode, MD, MPH, FACP Clinical Associate Professor of Medicine Muhammad Rajib Hossain, MD Michigan Medicine Harish Patel, MD, FACP University of Michigan Fatema S. Uddin, MD Ann Arbor, Michigan Seth Sweetser, MD Gastroenterology and Hepatology Associate Professor of Medicine ACP Editorial Staff Division of Gastroenterology and Hepatology Sandy Crump, Medical Editor, Assessment and Education Department of Medicine Programs Mayo Clinic School of Medicine Suzanne Meyers, Medical Editor, Assessment and Rochester, Minnesota Education Programs

Margaret Wells, Ed.M., Director, Assessment and Education Rotonya M. Carr, MD Programs Consultantship Becky Krumm, Senior Managing Editor, Assessment and Boehringer Education Programs Research Grants/Contracts Intercept ACP Principal Staff Davoren Chick, MD, FACP Other (Owner) Davoren Chick, MD, FACP Coding 101, LLC Senior Vice President, Medical Education Vani J.A. Konda, MD Tabassum Salam, MD, MBA, FACP Consultantship Vice President, Medical Education Mauna Kea Technologies Patrick C. Alguire, MD, FACP Honoraria MKSAP Senior Deputy Editor Pentax/C2 Therapeutics Research Grants/Contracts Margaret Wells, Ed.M. Ironwood Director, Assessment and Education Programs Pentax Becky Krumm Sonia S. Kupfer, MD Senior Managing Editor Research Grants/Contracts Immunovia Jackie Twomey Associate Managing Editor Benjamin Lebwohl, MD, MS Consultantship Julia Nawrocki Takeda, Innovate Biopharmaceuticals, Executive Digital Content Associate/Editor Health Examinations Linnea Donnarumma Board Member Senior Medical Editor Nima Labs

Becky Krumm Sonia S. Kupfer, MD Senior Managing Editor Research Grants/Contracts Immunovia Jackie Twomey Associate Managing Editor Benjamin Lebwohl, MD, MS Consultantship Julia Nawrocki Takeda, Innovate Biopharmaceuticals, Executive Digital Content Associate/Editor Health Examinations Linnea Donnarumma Board Member Senior Medical Editor Nima Labs Amanda Cowley Aimee Lucas, MD, MS Medical Editor Research Grants/Contracts Immunovia Sandy Crump Medical Editor Richard J. Saad, MD, MS Consultantship Georgette Forgione Takeda Pharmaceuticals Medical Editor Tabassum Salam, MD, MBA, FACP Beth Goldner Consultantship Medical Editor Johnson & Johnson Suzanne Meyers Seth Sweetser, MD Medical Editor Research Grants/Contracts Exact Sciences Elise Paxson Medical Editor

Amanda Cowley Aimee Lucas, MD, MS Medical Editor Research Grants/Contracts Immunovia Sandy Crump Medical Editor Richard J. Saad, MD, MS Consultantship Georgette Forgione Takeda Pharmaceuticals Medical Editor Tabassum Salam, MD, MBA, FACP Beth Goldner Consultantship Medical Editor Johnson & Johnson Suzanne Meyers Seth Sweetser, MD Medical Editor Research Grants/Contracts Exact Sciences Elise Paxson Medical Editor Chuck Graver Acknowledgments Finance and Operations Administrator The American College of Physicians (ACP) gratefully acknowledges the special contributions to the develop- Kimberly Kerns ment and production of the 19th edition of the Medical Administrative Coordinator Knowledge Self-Assessment Program (MKSAP* 19) made by the following people: Disclosures of relationships with any entity producing, marketing, reselling, or distributing health care goods or Graphic Design: Barry Moshinski (Director, Graphic services consumed by, or used on, patients. Individuals not Services), Mike Ripca (Technical Administrator, Graphic listed below have nothing to disclose. Services), Raymond DeJohn (Designer, Graphic Services)

Production/Systems: Dan Hoffmann (Director, Information Learning Objectives Technology), Scott Hurd (Manager, Content Systems), The learning objectives of MKSAP 19 are to: Neil Kohl (Senior Architect), and Chris Patterson (Senior Architect). ¢ Close gaps between actual care in your practice and preferred standards of care, based on best evidence MKSAP 19 Digital: Under the leadership of Steven Spadt ¢ Diagnose disease states that are less common and (Senior Vice President, Technology), the development sometimes overlooked or confusing of the digital version of MKSAP 19 was implemented by e Improve clinical management decisions that affect patient ACP’s Digital Products and Services Department, directed safety and quality of care and led by Brian Sweigard (Director, Digital Products e Determine when to refer patients for care by medical and Services). Other members of the team included Dan subspecialists, surgeons, and other members of the health Barron (Senior Web Application Developer/Architect), care team Callie Cramer (Data Visualization/Web Developer), Chris e Pass the ABIM Certification Examination Forrest (Senior Web Application Developer), Kathleen e Pass the ABIM Maintenance of Certification Examination Hoover (Senior Web Developer), Kara Regis (Manager, User Interface Design and Development), Brad Lord (Senior Web Application Developer/Architect), and John Target Audience McKnight (Senior Web Developer). ¢ General internal medicine specialists, including primary care physicians and hospitalists The College also wishes to acknowledge that many ¢ Internal medicine subspecialists who desire to remain up other persons, too numerous to mention, have contrib- to date in internal medicine uted to the production of this program. Without their e Residents preparing for the ABIM Internal Medicine dedicated efforts, this program would not have been Certification Examination possible. e Physicians engaged in the ABIM Maintenance of Certification Longitudinal Assessment Option, pre- MKSAP Resource Page paring for the ABIM Internal Medicine Maintenance of

Production/Systems: Dan Hoffmann (Director, Information Learning Objectives Technology), Scott Hurd (Manager, Content Systems), The learning objectives of MKSAP 19 are to: Neil Kohl (Senior Architect), and Chris Patterson (Senior Architect). ¢ Close gaps between actual care in your practice and preferred standards of care, based on best evidence MKSAP 19 Digital: Under the leadership of Steven Spadt ¢ Diagnose disease states that are less common and (Senior Vice President, Technology), the development sometimes overlooked or confusing of the digital version of MKSAP 19 was implemented by e Improve clinical management decisions that affect patient ACP’s Digital Products and Services Department, directed safety and quality of care and led by Brian Sweigard (Director, Digital Products e Determine when to refer patients for care by medical and Services). Other members of the team included Dan subspecialists, surgeons, and other members of the health Barron (Senior Web Application Developer/Architect), care team Callie Cramer (Data Visualization/Web Developer), Chris e Pass the ABIM Certification Examination Forrest (Senior Web Application Developer), Kathleen e Pass the ABIM Maintenance of Certification Examination Hoover (Senior Web Developer), Kara Regis (Manager, User Interface Design and Development), Brad Lord (Senior Web Application Developer/Architect), and John Target Audience McKnight (Senior Web Developer). ¢ General internal medicine specialists, including primary care physicians and hospitalists The College also wishes to acknowledge that many ¢ Internal medicine subspecialists who desire to remain up other persons, too numerous to mention, have contrib- to date in internal medicine uted to the production of this program. Without their e Residents preparing for the ABIM Internal Medicine dedicated efforts, this program would not have been Certification Examination possible. e Physicians engaged in the ABIM Maintenance of Certification Longitudinal Assessment Option, pre- MKSAP Resource Page paring for the ABIM Internal Medicine Maintenance of The MKSAP Resource Page (www.acponline.org/mksap19- Certification Examination, or engaged with the ABIM

Production/Systems: Dan Hoffmann (Director, Information Learning Objectives Technology), Scott Hurd (Manager, Content Systems), The learning objectives of MKSAP 19 are to: Neil Kohl (Senior Architect), and Chris Patterson (Senior Architect). ¢ Close gaps between actual care in your practice and preferred standards of care, based on best evidence MKSAP 19 Digital: Under the leadership of Steven Spadt ¢ Diagnose disease states that are less common and (Senior Vice President, Technology), the development sometimes overlooked or confusing of the digital version of MKSAP 19 was implemented by e Improve clinical management decisions that affect patient ACP’s Digital Products and Services Department, directed safety and quality of care and led by Brian Sweigard (Director, Digital Products e Determine when to refer patients for care by medical and Services). Other members of the team included Dan subspecialists, surgeons, and other members of the health Barron (Senior Web Application Developer/Architect), care team Callie Cramer (Data Visualization/Web Developer), Chris e Pass the ABIM Certification Examination Forrest (Senior Web Application Developer), Kathleen e Pass the ABIM Maintenance of Certification Examination Hoover (Senior Web Developer), Kara Regis (Manager, User Interface Design and Development), Brad Lord (Senior Web Application Developer/Architect), and John Target Audience McKnight (Senior Web Developer). ¢ General internal medicine specialists, including primary care physicians and hospitalists The College also wishes to acknowledge that many ¢ Internal medicine subspecialists who desire to remain up other persons, too numerous to mention, have contrib- to date in internal medicine uted to the production of this program. Without their e Residents preparing for the ABIM Internal Medicine dedicated efforts, this program would not have been Certification Examination possible. e Physicians engaged in the ABIM Maintenance of Certification Longitudinal Assessment Option, pre- MKSAP Resource Page paring for the ABIM Internal Medicine Maintenance of The MKSAP Resource Page (www.acponline.org/mksap19- Certification Examination, or engaged with the ABIM resources) provides access to MKSAP 19 online answer sheets Focused Practice in Hospital Medicine program

Production/Systems: Dan Hoffmann (Director, Information Learning Objectives Technology), Scott Hurd (Manager, Content Systems), The learning objectives of MKSAP 19 are to: Neil Kohl (Senior Architect), and Chris Patterson (Senior Architect). ¢ Close gaps between actual care in your practice and preferred standards of care, based on best evidence MKSAP 19 Digital: Under the leadership of Steven Spadt ¢ Diagnose disease states that are less common and (Senior Vice President, Technology), the development sometimes overlooked or confusing of the digital version of MKSAP 19 was implemented by e Improve clinical management decisions that affect patient ACP’s Digital Products and Services Department, directed safety and quality of care and led by Brian Sweigard (Director, Digital Products e Determine when to refer patients for care by medical and Services). Other members of the team included Dan subspecialists, surgeons, and other members of the health Barron (Senior Web Application Developer/Architect), care team Callie Cramer (Data Visualization/Web Developer), Chris e Pass the ABIM Certification Examination Forrest (Senior Web Application Developer), Kathleen e Pass the ABIM Maintenance of Certification Examination Hoover (Senior Web Developer), Kara Regis (Manager, User Interface Design and Development), Brad Lord (Senior Web Application Developer/Architect), and John Target Audience McKnight (Senior Web Developer). ¢ General internal medicine specialists, including primary care physicians and hospitalists The College also wishes to acknowledge that many ¢ Internal medicine subspecialists who desire to remain up other persons, too numerous to mention, have contrib- to date in internal medicine uted to the production of this program. Without their e Residents preparing for the ABIM Internal Medicine dedicated efforts, this program would not have been Certification Examination possible. e Physicians engaged in the ABIM Maintenance of Certification Longitudinal Assessment Option, pre- MKSAP Resource Page paring for the ABIM Internal Medicine Maintenance of The MKSAP Resource Page (www.acponline.org/mksap19- Certification Examination, or engaged with the ABIM resources) provides access to MKSAP 19 online answer sheets Focused Practice in Hospital Medicine program for transcribing answers from the print edition; access to MKSAP 19 Digital; Board Basics"; information on Continuing Earn CME Credits or MOC Points Online Medical Education (CME), Maintenance of Certification (MOC), To earn CME credits or to apply for MOC points, MKSAP and international Continuing Professional Development (CPD) users need to answer at least one of two questions correctly and MOC; errata; and other new information. (earning a score of at least 50%) and click the Submit CME button. Each single MKSAP 19 self-assessment question quali-

for transcribing answers from the print edition; access to MKSAP 19 Digital; Board Basics"; information on Continuing Earn CME Credits or MOC Points Online Medical Education (CME), Maintenance of Certification (MOC), To earn CME credits or to apply for MOC points, MKSAP and international Continuing Professional Development (CPD) users need to answer at least one of two questions correctly and MOC; errata; and other new information. (earning a score of at least 50%) and click the Submit CME button. Each single MKSAP 19 self-assessment question quali- International MOC/CPD fies for one quarter of a CME credit hour or ABIM MOC point.

for transcribing answers from the print edition; access to MKSAP 19 Digital; Board Basics"; information on Continuing Earn CME Credits or MOC Points Online Medical Education (CME), Maintenance of Certification (MOC), To earn CME credits or to apply for MOC points, MKSAP and international Continuing Professional Development (CPD) users need to answer at least one of two questions correctly and MOC; errata; and other new information. (earning a score of at least 50%) and click the Submit CME button. Each single MKSAP 19 self-assessment question quali- International MOC/CPD fies for one quarter of a CME credit hour or ABIM MOC point. Information and instructions on submission of international MKSAP 19 Subscribers can enter their self-assessment MOC/CPD is available by accessing the CME/MOC/CPD question answers and submit for CME/MOC in two ways: tab on the left navigation menu of MKSAP 19 Digital. 1. Users of MKSAP 19 Complete who prefer to use their print books and a paper answer sheet to study and Continuing Medical Education record their answers can use the printed answer sheet The American College of Physicians is accredited by the at the back of this book to record their answers. The Accreditation Council for Continuing Medical Education corresponding online answer sheets, which are avail- (ACCME) to provide continuing medical education for able on the MKSAP 19 Resource Page, may be used to physicians. transcribe answers onto the online answer sheets. Users may then submit their answers to qualify for CME cred- The American College of Physicians designates this endur- its or MOC points (see below for information on Opting ing material, MKSAP 19, for a maximum of 300 AMA PRA in for MOC). Users who prefer to record their answers Category 1 CreditsTM. Physicians should claim only the on a paper answer sheet should save their answer sheet credit commensurate with the extent of their participation for future use. Users who study with MKSAP 19 print in the activity. can also submit their answers directly within MKSAP 19 Up to 24 AMA PRA Category 1 CreditsTM are available from Digital by accessing the self-assessment questions dash- August 31, 2021, to August 31, 2024, for the MKSAP 19 board and selecting the preferred subspecialty section Gastroenterology and Hepatology section. to begin answering questions.

2. Users of MKSAP 19 Digital can enter their answers send any relevant comments to mksap_editors@acponline. within the digital program by accessing the self- org so that future decisions about content and contributors assessment questions dashboard and selecting the can be made in light of this information. preferred subspecialty section to begin answering questions and clicking the Submit CME button once they qualify for CME and are ready to submit. Learners Resolution of Conflicts should keep in mind their yearly CME and MOC dead- To resolve all conflicts of interest and influences of vested lines when determining the appropriate time to submit. interests, ACP’s content planners used best evidence and updated clinical care guidelines in developing content, Learners’ CME/MOC submission progress will be shown on when such evidence and guidelines were available. All the MKSAP 19 Digital CME/MOC/CPD page. content underwent review by external peer reviewers not on the committee to ensure that the material was bal- Opting in for MOC anced and unbiased. Contributors’ disclosure information can be found with the list of contributors’ names and MKSAP 19 users can opt in for simultaneous submission of those of ACP principal staff listed in the beginning of this CME and MOC points as they answer self-assessment ques- book. tions. To opt in, users will be required to complete a form requesting their name, date of birth, and ABIM number. The MOC Opt-in Form will be presented during a user’s Language Reflecting Diversity, Equity, first CME submission and needs to be completed only once. and Inclusion Within MKSAP 19 MKSAP 19’s Editors and contributors commit to using ABIM Maintenance of Certification language and images that support ACP’s commitment to being an anti-racist organization that supports diversity, Successful completion of the CME activity, which includes equity, and inclusion throughout health care and health participation in the evaluation component, enables the par- education. ACP also continues to ensure diversity among ticipant to earn up to 300 medical knowledge MOC points MKSAP’s physician-contributors. When appropriate, the in the ABIM’s MOC program. It is the CME activity provider’s MKSAP Editors will also rely on MKSAP 19 Digital’s expanded responsibility to submit participant completion information use of multimedia enhancements, including video and audio, to ACCME for the purpose of granting MOC credit. to explore and more fully explain issues surrounding the presentation of MKSAP 19 clinical content as it relates to Disclosure Policy race and ethnicity. MKSAP 19 users are encouraged to contact the Editors at mksap_editors@acponline.org to It is the policy of the American College of Physicians (ACP) help us identify opportunities for improvement in this to ensure balance, independence, objectivity, and scientific area. rigor in all of its educational activities. To this end, and consistent with the policies of the ACP and the Accreditation Council for Continuing Medical Education (ACCME), con- Hospital-Based Medicine tributors to all ACP continuing medical education activities are required to disclose all relevant financial relationships For the convenience of subscribers who provide care in with any entity producing, marketing, re-selling, or distrib- hospital settings, comprehensive hospital-focused content uting health care goods or services consumed by, or used aligned with the ABIM Focused Practice in Hospital Medicine on, patients. Contributors are required to use generic names blueprint is integrated throughout the syllabus, and self- in the discussion of therapeutic options and are required assessment questions that are specific to the hospital setting to identify any unapproved, off-label, or investigative use are specially designated with the blue hospitalist icon (). of commercial products or devices. Where a trade name is used, all available trade names for the same product type are also included. If trade-name products manufactured High Value Care Key Points by companies with whom contributors have relation- Key Points in the text that relate to High Value Care concepts ships are discussed, contributors are asked to provide (that is, concepts that discuss balancing clinical benefit with evidence-based citations in support of the discussion. The costs and harms) are designated by the HVC icon [HVC]. information is reviewed by the committee responsible for producing this content. If necessary, adjustments to topics or contributors’ roles in content development are made to Educational Disclaimer balance the discussion. Further, all readers of this content The editors and publisher of MKSAP 19 recognize that the are asked to evaluate it for evidence of commercial bias and development of new material offers many opportunities

2. Users of MKSAP 19 Digital can enter their answers send any relevant comments to mksap_editors@acponline. within the digital program by accessing the self- org so that future decisions about content and contributors assessment questions dashboard and selecting the can be made in light of this information. preferred subspecialty section to begin answering questions and clicking the Submit CME button once they qualify for CME and are ready to submit. Learners Resolution of Conflicts should keep in mind their yearly CME and MOC dead- To resolve all conflicts of interest and influences of vested lines when determining the appropriate time to submit. interests, ACP’s content planners used best evidence and updated clinical care guidelines in developing content, Learners’ CME/MOC submission progress will be shown on when such evidence and guidelines were available. All the MKSAP 19 Digital CME/MOC/CPD page. content underwent review by external peer reviewers not on the committee to ensure that the material was bal- Opting in for MOC anced and unbiased. Contributors’ disclosure information can be found with the list of contributors’ names and MKSAP 19 users can opt in for simultaneous submission of those of ACP principal staff listed in the beginning of this CME and MOC points as they answer self-assessment ques- book. tions. To opt in, users will be required to complete a form requesting their name, date of birth, and ABIM number. The MOC Opt-in Form will be presented during a user’s Language Reflecting Diversity, Equity, first CME submission and needs to be completed only once. and Inclusion Within MKSAP 19 MKSAP 19’s Editors and contributors commit to using ABIM Maintenance of Certification language and images that support ACP’s commitment to being an anti-racist organization that supports diversity, Successful completion of the CME activity, which includes equity, and inclusion throughout health care and health participation in the evaluation component, enables the par- education. ACP also continues to ensure diversity among ticipant to earn up to 300 medical knowledge MOC points MKSAP’s physician-contributors. When appropriate, the in the ABIM’s MOC program. It is the CME activity provider’s MKSAP Editors will also rely on MKSAP 19 Digital’s expanded responsibility to submit participant completion information use of multimedia enhancements, including video and audio, to ACCME for the purpose of granting MOC credit. to explore and more fully explain issues surrounding the presentation of MKSAP 19 clinical content as it relates to Disclosure Policy race and ethnicity. MKSAP 19 users are encouraged to contact the Editors at mksap_editors@acponline.org to It is the policy of the American College of Physicians (ACP) help us identify opportunities for improvement in this to ensure balance, independence, objectivity, and scientific area. rigor in all of its educational activities. To this end, and consistent with the policies of the ACP and the Accreditation Council for Continuing Medical Education (ACCME), con- Hospital-Based Medicine tributors to all ACP continuing medical education activities are required to disclose all relevant financial relationships For the convenience of subscribers who provide care in with any entity producing, marketing, re-selling, or distrib- hospital settings, comprehensive hospital-focused content uting health care goods or services consumed by, or used aligned with the ABIM Focused Practice in Hospital Medicine on, patients. Contributors are required to use generic names blueprint is integrated throughout the syllabus, and self- in the discussion of therapeutic options and are required assessment questions that are specific to the hospital setting to identify any unapproved, off-label, or investigative use are specially designated with the blue hospitalist icon (). of commercial products or devices. Where a trade name is used, all available trade names for the same product type are also included. If trade-name products manufactured High Value Care Key Points by companies with whom contributors have relation- Key Points in the text that relate to High Value Care concepts ships are discussed, contributors are asked to provide (that is, concepts that discuss balancing clinical benefit with evidence-based citations in support of the discussion. The costs and harms) are designated by the HVC icon [HVC]. information is reviewed by the committee responsible for producing this content. If necessary, adjustments to topics or contributors’ roles in content development are made to Educational Disclaimer balance the discussion. Further, all readers of this content The editors and publisher of MKSAP 19 recognize that the are asked to evaluate it for evidence of commercial bias and development of new material offers many opportunities vi

Gastroenterology and Hepatology Disorders of the Esophageal Dysphagia Patients with esophageal dysphagia can initiate the swallowing Esophagus process but often feel chest discomfort. Patients also may not readily characterize dysphagia as difficulty swallowing. Symptoms of Esophageal Disease Common descriptions of the sensations of dysphagia include Dysphagia food “hanging up” or feeling lodged or stuck during a meal. Normal swallowing consists of three phases. The oral phase Patients also may describe a bolus slow to go down or “sitting” encompasses formation of a food bolus and transfer of the in the chest. Occasionally they may present with vomiting of bolus to the back of the throat. The pharyngeal phase allows undigested food contents. the bolus to be safely positioned in the upper throat; the soft Esophageal dysphagia results from one of two causes: a palate elevates, the epiglottis protects the trachea, the tongue mechanical obstruction or a motility disorder. Dysphagia with moves backward, and the pharyngeal wall moves forward. The solids alone suggests a mechanical obstruction, whereas dys- esophageal phase starts with the bolus entering the esophagus phagia with liquids alone or with liquids and solids favors a with relaxation of the upper esophageal sphincter. Peristalsis motility disorder. An urgent workup is indicated for complete (rhythmic contractions) propels the bolus down; primary per- obstruction, hematemesis, odynophagia, onset in an older istalsis is initiated with the swallow, and secondary peristalsis patient, dysphagia associated with weight loss, or acute course. is intended to clear residual bolus. This phase ends as the Food impaction may occur, wherein a food bolus lodges in the lower esophageal sphincter relaxes to allow the bolus to enter esophagus and obstructs the passage of additional food, fluid, the stomach. or saliva. Food impaction is an indication for emergency

is intended to clear residual bolus. This phase ends as the Food impaction may occur, wherein a food bolus lodges in the lower esophageal sphincter relaxes to allow the bolus to enter esophagus and obstructs the passage of additional food, fluid, the stomach. or saliva. Food impaction is an indication for emergency Dysphagia is a disruption in the swallowing mechanism, endoscopy. resulting in a bolus not passing from the mouth to the stom- Mechanical esophageal obstruction may be benign or ach. Determining whether the cause is oropharyngeal or malignant and may be caused by masses, strictures, an esoph- esophageal is important in developing a differential diagnosis ageal ring (e.g., a Schatzki ring [Figure 1]), webs, or complex and management plan. Table 1 highlights common causes of hiatal hernias. Strictures may be due to chronic reflux dysphagia. esophagitis (peptic strictures), eosinophilic esophagitis, radia- tion therapy, or caustic injury. Dysphagia that progresses from Oropharyngeal Dysphagia occurring only with solids to occurring with both solids and Oropharyngeal dysphagia, also called transfer dysphagia, liquids is concerning because it may be indicative of malig- occurs when the patient cannot transfer the food bolus from nancy or of benign strictures that have become high-grade the mouth into the upper esophagus by swallowing. Common obstructions. Achalasia often presents with dysphagia for both symptoms include choking, coughing, and nasal regurgita- solids and liquids associated with nonacidic regurgitation of tion of food and liquids. Patients are at risk for aspiration undigested food and fluid. Chest pain upon ingestion of very pneumonia. Stroke is a common cause, and an underlying hot or very cold liquids may indicate esophageal spasm. neurologic disorder, such as Parkinson disease, may be sus- Upper endoscopy allows for diagnosis (biopsy and inspec-

tion of food and liquids. Patients are at risk for aspiration undigested food and fluid. Chest pain upon ingestion of very pneumonia. Stroke is a common cause, and an underlying hot or very cold liquids may indicate esophageal spasm. neurologic disorder, such as Parkinson disease, may be sus- Upper endoscopy allows for diagnosis (biopsy and inspec- pected, particularly with concurrent neurologic findings. A tion) and therapeutic intervention (dilation) and is the usual pharyngoesophageal (Zenker) diverticulum should be con- initial test of choice. Barium esophagography may provide sidered when undigested food is brought up several hours more information in specific situations, such as suspicion of after a meal or if a patient reports hearing a gurgling noise in motility disorders or proximal lesions (e.g., Zenker diverticu- the throat. lum). Clinical management is based on the underlying cause. The initial study for suspected oropharyngeal dyspha- gia is a modified barium swallow and video fluoroscopy, Odynophagia with a range of liquid and solid consistencies. Routine Pain while swallowing defines odynophagia and suggests upper gastrointestinal endoscopy and esophageal manom- active mucosal inflammation and esophageal ulceration. etry have a limited role in the evaluation of oropharyngeal Odynophagia is commonly associated with pill-induced dam- dysphagia. Management includes dietary changes and a age, infection, or caustic ingestion and is less commonly swallowing exercise program implemented with a speech caused by gastroesophageal reflux disease (GERD) or esopha- pathologist. geal cancer. Upper endoscopy with biopsy is the most