Washington manual of gastroenterology 3rd ed subspeciality consult PDFtahir99 VRG

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Library of Congress Cataloging-in-Publication Data
The Washington manual gastroenterology subspecialty consult / editor, C.
Prakash Gyawali. — 3rd ed.
p. ; cm. — (Washington manual subspecialty consult series)
Includes bibliographical references and index.
ISBN 978-1-4511-1410-2 (alk. paper) — ISBN 1-4511-1410-9 (alk. paper)
I. Gyawali, C. Prakash. II. Series: Washington manual subspecialty
consult series.

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Anupam Aditi, MD
Resident
Department of Internal Medicine
Washington University School of Medicine
St. Louis, Missouri
Akwi W. Asombang, MD
Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Riad Azar, MD

Associate Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Elizabeth Blaney, MD
Resident
Department of Internal Medicine
Washington University School of Medicine
St. Louis, Missouri
Benjamin E. Cassell, MD
Resident
Department of Internal Medicine
6


Washington University School of Medicine
St. Louis, Missouri
Chien-Huan Chen, MD
Assistant Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Reena V. Chokshi, MD
Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Matthew A. Ciorba, MD
Assistant Professor of Medicine
Division of Gastroenterology

Washington University School of Medicine
St. Louis, Missouri
Jeffrey S. Crippin, MD
Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Dayna S. Early, MD
Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Darrell M. Gray, II, MD
7


Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
C. Prakash Gyawali, MD, MRCP
Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Heba Iskandar, MD
Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri

John M. Iskander, MD
Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Sreenivasa Jonnalagadda, MD
Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Thomas A. Kerr, MD
Assistant Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri

8


Kevin M. Korenblat, MD
Associate Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Gowri Kularatna, MD
Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Mridula V. Kumar, MD

Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Vladimir Kushnir, MD
Fellow
Division of Gastroenterology
Washington University School of Medicine St. Louis, Missouri
Alexander Lee, MD
Resident
Department of Internal Medicine
Washington University School of Medicine
St. Louis, Missouri
Mauricio Lisker-Melman, MD
Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri

9


Faiz Mirza, MD
Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Daniel Mullady, MD
Associate Professor of Medicine
Division of Gastroenterology

Washington University School of Medicine
St. Louis, Missouri
Amit Patel, MD
Resident
Department of Internal Medicine
Washington University School of Medicine
St. Louis, Missouri
Nishant J. Patel, MD
Resident
Department of Internal Medicine
Washington University School of Medicine
St. Louis, Missouri
Andrew Reinink, MD
Resident
Department of Internal Medicine
Washington University School of Medicine
St. Louis, Missouri
Gregory S. Sayuk
Assistant Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
10


Jonathan Seccombe, MD
Resident
Department of Internal Medicine
Washington University School of Medicine
St. Louis, Missouri

Anil B. Seetharam, MD
Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Anisa Shaker, MD
Assistant Professor of Medicine
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Noura M. Sharabash, MD
Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Jennifer Shroff, MD
Resident
Department of Internal Medicine
Washington University School of Medicine
St. Louis, Missouri
A. Samad Soudagar, MD
Resident
Department of Internal Medicine
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Washington University School of Medicine
St. Louis, Missouri
Shelby A. Sullivan, MD
Assistant Professor of Medicine

Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Hongha (Susan) T. Vu, MD
Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri
Sachin Wani, MD
Advanced Fellow
Division of Gastroenterology
Washington University School of Medicine
St. Louis, Missouri

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t is a pleasure to present the new edition of The Washington Manual®
Subspecialty Consult Series: Gastroenterology Subspecialty Consult. This pocketsize book continues to be a primary reference for medical students, interns,
residents, and other practitioners who need ready access to practical clinical
information to diagnose and treat patients with a wide variety of disorders. Medical
knowledge continues to increase at an astounding rate, which creates a challenge for
physicians to keep up with the biomedical discoveries, genetic and genomic
information, and novel therapeutics that can positively impact patient outcomes. The
Washington Manual Subspecialty Consult Series addresses this challenge by
concisely and practically providing current scientific information for clinicians to
aid them in the diagnosis, investigation, and treatment of common medical
conditions.
I want to personally thank the authors, which include house officers, fellows,
and attendings at Washington U niversity School of Medicine and Barnes Jewish

Hospital. Their commitment to patient care and education is unsurpassed, and their
efforts and skill in compiling this manual are evident in the quality of the final
product. In particular, I would like to acknowledge our editor Dr. C. Prakash
Gyawali and the series editors Drs. Katherine Henderson and Tom De Fer, who
have worked tirelessly to produce another outstanding edition of this manual. I
would also like to thank Dr. Melvin Blanchard, Chief of the Division of Medical
Education, Department at of Medicine, Washington University School of Medicine,
for his advice and guidance. I believe this Manual will meet its desired goal of
providing practical knowledge that can be directly applied at the bedside and in
outpatient settings to improve patient care.
Victoria J. Fraser, MD
Dr. J. William Campbell Professor
Interim Chairman of Medicine
Codirector, Infectious Disease Division
Washington University School of Medicine
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astroenterology continues to expand as a specialty, with a wealth of new
insights on disease pathophysiology, diagnostic tools, and management options. In
addition, certain disorders such as eosinophilic esophagitis, autoimmune enteropathy
and autoimmune pancreatitis are being increasingly recognized and managed.
Genetic testing now has a defined role in many gastrointestinal disorders, including
colon cancer, and is actively utilized in clinical gastroenterology. Given these
advances, it is clear that there is ongoing need for easy access of concise diagnostic
and management direction for the novice and intermediate trainee, a need that this
manual fulfills. The unique aspect of this manual is that it is conceived and written
by trainees for trainees, with extensive mentoring and editing from academic faculty
experts. The manual therefore describes symptoms and disease entities that are
encountered most often in clinical units, both ambulatory and inpatient. The manual

strives to provide a succinct yet descriptive synopsis of each condition, presenting
the reader with disease characteristics, clinical features, investigation, and
management.
With the widespread distribution and review of the second edition of the
manual, it became evident that certain areas needed additional emphasis. The format
of individual diseases and symptoms has been revised to follow specific
subheadings to bring uniformity to the manual and to the Subspecialty Consult Series
as a whole. The manual has been extensively updated. Two new chapters are
included, Liver Transplantation and Genetic Testing in Gastrointestinal Diseases. In
addition, the chapter on Nutrition has been revised to reflect Malnutrition. Extended
segments have been updated, and in some cases, entire chapters have been rewritten
by current Washington University internal medicine residents aspiring to become
gastroenterologists and gastroenterology fellows currently enrolled in fellowship
traini ng, all under the watchful eyes of faculty experts. The third edition of the
manual therefore represents an up-to-date yet concise treatise on current knowledge
of common gastrointestinal ailments.
I would like to extend my gratitude to all the trainees and faculty mentors who
worked tirelessly to ensure that their chapters were updated and that they conformed
14


to the revised formats. For our trainee authors entering the field of gastroenterology,
seeing their contributions in print will hopefully provide them renewed enthusiasm
and vigor for continued scholarship and education, and ultimately the opportunity to
return the favor by furthering education of future trainees.
—C.P.G.

15

Contributing Authors
Chairman’s Note
Preface
PART I. APPROACH TO SPECIFIC SYMPTOMS
1. Dysphagia
Faiz Mirza
2. Nausea and Vomiting
Vladimir Kushnir and C. Prakash Gyawali
3. Diarrhea
Hongha (Susan) T. Vu
4. Constipation
Reena V. Chokshi
5. Abdominal Pain
Akwi W. Asombang
6. Acute Gastrointestinal Bleeding
Darrell M. Gray, II
7. Occult and Obscure Gastrointestinal Bleeding
John M. Iskander
8. Jaundice
Noura M. Sharabash
9. Abnormal Liver Chemistries
Noura M. Sharabash
16


10. Ascites
Mrudula V. Kumar
11. Malnutrition
Gowri Kularatna and Shelby A. Sullivan
PART II. APPROACH TO SPECIFIC DISEASES

12. Esophageal Disorders
Jonathan Seccombe and C. Prakash Gyawali
13. Gastric Disorders
Amit Patel and C. Prakash Gyawali
14. Small Bowel Disorders
A. Samad Soudagar and Anisa Shaker
15. Colon Neoplasms
Nishant J. Patel and Dayna S. Early
16. Inflammatory Bowel Disease
Heba Iskandar and Matthew A. Ciorba
17. Irritable Bowel Syndrome
Benjamin E. Cassell and Gregory S. Sayuk
18. Acute Liver Disease
Anil B. Seetharam and Kevin M. Korenblat
19. Chronic Liver Disease
Jennifer Shroff and Mauricio Lisker-Melman
20. Cirrhosis
Anupam Aditi and Jeffrey S. Crippin
21. Liver Transplantation
Anil B. Seetharam and Thomas A. Kerr
22. Pancreatic Disorders
17


Alexander Lee and Sreenivasa Jonnalagadda
23. Biliary Tract Disorders
Riad Azar and Andrew Reinink
24. Genetic Testing in Gastrointestinal Diseases
Elizabeth Blaney and Chien-Huan Chen
25. Gastrointestinal Procedures

Sachin Wani and Daniel Mullady
Index

18


GENERAL PRINCIPLES
Dysphagia is a common patient complaint that requires prompt
evaluation and management.
Definition

Dysphagia is defined as difficulty in swallowing or the sensation of
an obstruction in the passage of food (semisolid, solid, and/or
liquid) anywhere from the mouth to the stomach.1
Dysphagia should be distinguished from the following:
Odynophagia: pain during swallowing (dysphagia and odynophagia
may coexist in the same patient).
Globus: constant sensation of a lump or fullness in throat without
difficulty swallowing.
Aphagia: inability to swallow, which can result when a food bolus gets
impacted in the esophagus, thus blocking passage of any further boluses.
Aphagia can also result from pharyngeal muscle paralysis from lower
cranial nerve involvement.
Xerostomia: dryness of the mouth from decreased salivation (from
Sjogren’s syndrome, radiation to head and neck, medication side effects,
etc.), which can cause trouble initiating a swallow because of poor
lubrication of the food bolus.
Classification

Dysphagia can be classified as oropharyngeal or esophageal.1

19


Oropharyngeal dysphagia
Arises from disorders that affect the function of the oropharynx, larynx,
and upper esophageal sphincter (UES).
Typically caused by lesions of the swallowing center, cranial nerves, or
oropharyngeal muscles, mucosa, or teeth.2
Results from defects in oral and pharyngeal phases of swallowing.3
These disorders cause difficulties with preparing the food for swallowing
or with transferring a bolus of food from oral cavity to esophagus.
Patients with oropharyngeal dysphagia may report difficulty initiating a
swallow, coughing, choking, drooling, or nasal regurgitation. This
sensation is typically reported within 1 second of initiating a swallow.3
Esophageal dysphagia
Arises commonly from structural defects within the body of the
esophagus, the lower esophageal sphincter (LES), or gastric cardia.
May be caused by diseases of the esophageal smooth muscle, the
autonomic nervous system, and/or mucosa of the esophagus.2
Dysphagia is typically reported with solid foods initially.
Can result from motor abnormalities in lower esophageal sphincter
relaxation or the esophageal phase of swallowing. Dysphagia can result
from both solids and liquids in neuromuscular disorders.
Patients may describe the sensation of food sticking in the throat or the
chest, retrosternal chest pain, or regurgitation soon after swallowing.
The regurgitate may taste similar to food just eaten and not sour or
bitter (which implicates retrograde transit from the stomach, as in reflux
disease or emesis).
The sensation of dysphagia may be referred to the sternal notch despite
the fact that the point of obstruction may be in the distal esophagus.

Epidemiology

It is estimated that nearly 16% to 22% of individuals older than 50 years
describe symptoms of dysphagia.3
Etiology

Oropharyngeal dysphagia is most commonly caused by neurogenic and
myogenic disorders and rarely occurs as a result of oropharyngeal or
base-of-skull tumors.
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Esophageal dysphagia is either the result of a structural esophageal
(luminal, intramural or extraluminal) lesion or a neuromuscular disorder
of esophageal peristalsis. In recent years, eosinophilic esophagitis, an
idiopathic eosinophilic inflammatory disease with remodeling of the
esophagus, is becoming increasingly recognized as a cause for
esophageal dysphagia, particularly in young adults.
Pathophysiology

The normal swallowing process can be divided into three
phases4:
Oral: The food bolus is first mechanically prepared by the muscles of the
jaw, face, and tongue, and propelled posteriorly and superiorly by the
tongue and the palate. This process lasts 1 to 2 seconds.
Pharyngeal: This phase begins when the bolus passes the anterior
tonsillar pillars. The soft palate closes the nasopharynx, and the lips and
the jaws remain closed. The larynx elevates and closes the laryngeal
valves (epiglottis and vocal cords). This also opens the upper esophageal
sphincter, allowing passage of the bolus into the esophagus. The entire

process lasts 1 second.
Esophageal: This phase begins with the entry of the bolus into the
esophagus. The upper esophageal sphincter closes, and bolus is
propelled efficiently through the esophagus to the stomach. In the
upright position, this is facilitated by gravity, with the esophageal muscle
contraction stripping the remnants of the bolus through an open lower
esophageal sphincter. Secondary esophageal peristalsis may initiate in
response to esophageal distension if the primary peristaltic effort is
insufficient in propelling the bolus.
Dysphagia is caused by a disruption in this process
Oropharyngeal dysphagia: occurs when there is a disruption in the
oral or pharyngeal phases of swallowing.
Esophageal dysphagia: occurs when there is a disruption in the
esophageal phase of swallowing.
Clinical Presentation

Oropharyngeal
Oropharyngeal dysphagia is commonly a manifestation of a
systemic disorder (Table 1-1). A careful and directed history
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specifically intended to include or rule out neurologic, muscular, collagen
vascular, and local structural disorders is essential.
Patients complain of difficulty initiating a swallow, coughing, choking,
drooling, or nasal regurgitation within 1 second of initiating a swallow.
Patients have difficulty with swallowing solids and/or liquids.
Evidence of neurologic dysfunction in the lower cranial nerves, or of
generalized muscle weakness or dystrophy may be evident on physical
examination.

Esophageal
Esophageal dysphagia is typically related to an esophageal
process, either structural or neuromuscular.
Patients complain of food sticking in the throat or the chest.
Symptoms start a few seconds after swallowing.
Patients have difficulty swallowing solids at the start, particularly with
structural lesions. This can progress to difficulty with liquids. Motor
disorders may be associated with dysphagia to both solids and liquids.
Regurgitation and chest pain may be associated symptoms.
History

A carefully taken symptom history can provide clues to the underlying
cause of dysphagia.3

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It is important to determine whether the patient has esophageal or
oropharyngeal dysphagia.3 The following are factors important in making
this determination:
Duration of symptoms and acuity of onset
Whether symptoms are intermittent or progressive
The presence or absence of aspiration symptoms, that is, cough or
choking episodes while swallowing
Symptoms of lower cranial nerve dysfunction, such as regurgitation
through the nose, drooling, or food spilling from the corners of the mouth
Associated symptoms like heartburn or chest pain
Medications the patient takes (including over-the-counter medications).
Medications that are commonly prescribed can cause dysphagia in the
oropharyngeal or esophageal stages of swallowing. For example,

tetracycline, clindamycin, and doxycycline can cause direct esophageal
mucosal injury.5
Other preexisting medical conditions, including atopic disorders and
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asthma, which may be relevant in eosinophilic esophagitis
The patients can be asked to describe where they feel the disturbance is
located
Food items that typically cause difficulty (specifically, solids, liquids, or
both)
History of radiation therapy to head and neck
The presence of weight loss1
Physical Examination

General examination: evaluate nutritional status (including body weight).
Complete neurologic examination (attention to resting tremor, cranial
nerves, and muscle strength).
Examine oral cavity, head, and neck.
If the patient describes easy fatigability, observe the patient while
performing a repetitive task (e.g., blinking, counting aloud).3
Observe the patient’s gait and balance (one reason for this is to check for
Parkinson’s disease).
Examine the skin for thickening or texture changes (especially palms of
hands and the soles of feet).1
Evaluate the neck for thyromegaly or other mass.
Inspect the muscles for wasting and fasciculations and palpate for
tenderness to detect an underlying motor neuron disease.3
Differential Diagnosis

Oropharyngeal dysphagia
Neuromuscular causes are more frequent than structural causes for this
type of dysphagia. This is mainly because the nerves that control the
muscles in this region have a direct connection to the brain through
cranial nerves and can be damaged in accidents or diseases that affect
the brain or the cranial nerves.3
Table 1-1 refers to some of the more frequent causes of oropharyngeal
dysphagia.
Esophageal dysphagia
Generally, structural causes are a more frequent cause of this type of
dysphagia than disorders involving nerves and muscles.
A structural disorder will initially cause dysphagia to solid foods but may
24


later include liquids as well. Eosinophilic esophagitis can present with
intermittent food bolus impactions.

Patients with a neuromuscular disorder commonly report dysphagia to
both solids and liquids from the onset of symptoms.1
Table 1-2 refers to some of the more frequent causes of esophageal
dysphagia.
Diagnostic Testing

If oropharyngeal dysphagia is suspected:
A careful neurologic examination is the first step in evaluation.
Modified barium swallow/videofluoroscopy4: This consists of a
radiographic study in which the oral and pharyngeal phases are observed
in real time while the patient swallows barium of varying consistencies,
such as thin liquids, thick liquids, and barium cookies, or a cracker. This

study helps identify abnormalities of the oropharyngeal phases and may
direct therapy. Patients may tolerate certain consistencies better than
others, and the diet can be modified accordingly.
Laryngoscopy: If structural lesions are identified, direct laryngoscopy
should be performed for further evaluation.
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