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Medical Knowledge Self-Assessment ProgramÂŽ

Gastroenterology and Hepatology

16 AMA PRA Category 1 Credits™ available until July 31, 2018.


Table of Contents Disorders of the Esophagus Symptoms of Esophageal Disorders . . . . . . . . . . . . . . . . . . 1 Dysphagia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Reflux and Chest Pain. . . . . . . . . . . . . . . . . . . . . . . . . . 1 Odynophagia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Globus Sensation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Nonmalignant Disorders of the Esophagus . . . . . . . . . . . . 3 Esophageal Motility Disorders. . . . . . . . . . . . . . . . . . . 3 Infectious, Pill-Induced, and Eosinophilic Esophagitis . . . . . . . . . . . . . . . . . . . . . . 6 Gastroesophageal Reflux Disease . . . . . . . . . . . . . . . . 7 Metaplastic and Neoplastic Disorders of the Esophagus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Barrett Esophagus. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Esophageal Carcinoma. . . . . . . . . . . . . . . . . . . . . . . . 11

Disorders of the Stomach and Duodenum Peptic Ulcer Disease. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Clinical Features, Diagnosis, and Complications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Dyspepsia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Clinical Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Helicobacter pylori Infection . . . . . . . . . . . . . . . . . . . . . . 14 Indications for Helicobacter pylori Testing. . . . . . . 14 Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Eradication Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Miscellaneous Gastropathy . . . . . . . . . . . . . . . . . . . . . . . . 17 Atrophic Gastritis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Intestinal Metaplasia. . . . . . . . . . . . . . . . . . . . . . . . . . 17 Eosinophilic Gastritis. . . . . . . . . . . . . . . . . . . . . . . . . 18 Lymphocytic Gastritis. . . . . . . . . . . . . . . . . . . . . . . . . 18 Gastrointestinal Complications of NSAIDs, Aspirin, and Anticoagulants . . . . . . . . . . . . . . . . . . . . . . . 18 Epidemiology and Risk Factors. . . . . . . . . . . . . . . . . 18 Prevention of NSAID-Induced Injury. . . . . . . . . . . . 18 Gastroparesis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Gastric Polyps and Subepithelial Lesions. . . . . . . . . . . . 20 Gastric Polyps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Gastric Subepithelial Lesions. . . . . . . . . . . . . . . . . . 20

Gastric Adenocarcinoma . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Epidemiology and Risk Factors. . . . . . . . . . . . . . . . . 21 Screening and Surveillance. . . . . . . . . . . . . . . . . . . . 21 Clinical Manifestations and Diagnosis . . . . . . . . . . . 21 Complications of Gastric Surgical Procedures. . . . . . . . . 22 Bariatric Surgery Complications. . . . . . . . . . . . . . . . 22 Other Gastric Resection Complications. . . . . . . . . . 23

Disorders of the Pancreas Acute Pancreatitis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Clinical Presentation and Diagnosis. . . . . . . . . . . . . 24 Prognostic Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Complications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Chronic Pancreatitis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Clinical Presentation and Diagnosis. . . . . . . . . . . . . 26 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Pancreatic Adenocarcinoma . . . . . . . . . . . . . . . . . . . . . . . 27 Clinical Presentation. . . . . . . . . . . . . . . . . . . . . . . . . . 28 Diagnosis and Staging. . . . . . . . . . . . . . . . . . . . . . . . . 28 Ampullary Adenocarcinoma. . . . . . . . . . . . . . . . . . . . . . . 28 Autoimmune Pancreatitis and IgG4 Disease . . . . . . . . . . 29 Clinical Presentation and Diagnosis. . . . . . . . . . . . . 29 Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Cystic Neoplasms of the Pancreas. . . . . . . . . . . . . . . . . . . 29 Pancreatic Neuroendocrine Tumors. . . . . . . . . . . . . . . . . 31

Disorders of the Small and Large Bowel Diarrhea. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Evaluation and Management. . . . . . . . . . . . . . . . . . . 32 Malabsorption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Celiac Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Small Intestinal Bacterial Overgrowth . . . . . . . . . . 36 Short-Bowel Syndrome. . . . . . . . . . . . . . . . . . . . . . . 36 Carbohydrate Malabsorption. . . . . . . . . . . . . . . . . . 36 Inflammatory Bowel Disease. . . . . . . . . . . . . . . . . . . . . . . 37 Risk Factors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Clinical Manifestations. . . . . . . . . . . . . . . . . . . . . . . . 37 Extraintestinal Manifestations. . . . . . . . . . . . . . . . . . 38 Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Health Maintenance for the Patient with Inflammatory Bowel Disease. . . . . . . . . . . . . . . . . . . 41 Microscopic Colitis . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 ix

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Constipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Classification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Irritable Bowel Syndrome. . . . . . . . . . . . . . . . . . . . . . . . . 43 Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Diverticular Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Ischemic Bowel Disease. . . . . . . . . . . . . . . . . . . . . . . . . . 46 Acute Mesenteric Ischemia. . . . . . . . . . . . . . . . . . . . 46 Chronic Mesenteric Ischemia. . . . . . . . . . . . . . . . . . . 47 Colonic Ischemia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Anorectal Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Perianal Disorders. . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Fecal Incontinence . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Anal Cancer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Colorectal Neoplasia Epidemiology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Pathogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Risk Factors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Modifiable Factors. . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Predisposing Factors. . . . . . . . . . . . . . . . . . . . . . . . . 49 Nonsyndromic Family History. . . . . . . . . . . . . . . . . 49 Hereditary Colon Cancer Syndromes. . . . . . . . . . . 50 Screening. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Chemoprevention. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Clinical Presentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Diagnosis and Staging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Surveillance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 History of Adenomatous and Serrated Polyps. . . . . 53 History of Colorectal Cancer . . . . . . . . . . . . . . . . . . . 53 Hereditary Nonpolyposis Colon Cancer. . . . . . . . . . 53 Familial Adenomatous Polyposis and MYH-Associated Polyposis. . . . . . . . . . . . . . . . . . . . . 54 Ulcerative or Crohn Colitis. . . . . . . . . . . . . . . . . . . . . 54 Peutz-Jeghers Syndrome . . . . . . . . . . . . . . . . . . . . . . 54 Other Syndromes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Disorders of the Liver Approach to the Patient with Abnormal Liver Chemistry Studies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Viral Hepatitis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Hepatitis A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Hepatitis B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Hepatitis C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Hepatitis D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Hepatitis E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Other Viruses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Alcohol-Induced Liver Disease . . . . . . . . . . . . . . . . . . . . 59

Drug-Induced Liver Injury. . . . . . . . . . . . . . . . . . . . . . . . 59 Acute Liver Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Autoimmune Hepatitis. . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Metabolic Liver Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Nonalcoholic Fatty Liver Disease. . . . . . . . . . . . . . . . 62 Hereditary Hemochromatosis. . . . . . . . . . . . . . . . . . 62 Îą1-Antitrypsin Deficiency . . . . . . . . . . . . . . . . . . . . 63 Wilson Disease. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Cholestatic Liver Diseases . . . . . . . . . . . . . . . . . . . . . . . . 63 Primary Biliary Cirrhosis. . . . . . . . . . . . . . . . . . . . . 63 Primary Sclerosing Cholangitis. . . . . . . . . . . . . . . . 64 Determining Prognosis. . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Complications of Advanced Liver Disease . . . . . . . . . . . 64 Portal Hypertension . . . . . . . . . . . . . . . . . . . . . . . . . 65 Esophageal Varices . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Gastric Varices and Portal Hypertensive Gastropathy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Hepatic Encephalopathy. . . . . . . . . . . . . . . . . . . . . . 66 Hepatopulmonary Syndrome . . . . . . . . . . . . . . . . . . 67 Portopulmonary Hypertension. . . . . . . . . . . . . . . . . 67 Ascites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Spontaneous Bacterial Peritonitis. . . . . . . . . . . . . . 68 Hepatorenal Syndrome. . . . . . . . . . . . . . . . . . . . . . . 69 Health Care Maintenance of the Patient with Chronic Liver Disease. . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Hepatic Osteodystrophy. . . . . . . . . . . . . . . . . . . . . . 69 Immunizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Avoidances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Nutrition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Hepatic Tumors, Cysts, and Abscesses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Hepatic Cysts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Focal Nodular Hyperplasia. . . . . . . . . . . . . . . . . . . . . 70 Hepatocellular Adenoma. . . . . . . . . . . . . . . . . . . . . . 71 Hepatic Hemangioma. . . . . . . . . . . . . . . . . . . . . . . . . 71 Hepatic Abscesses. . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Amebiasis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Hepatocellular Carcinoma. . . . . . . . . . . . . . . . . . . . . 71 Liver Transplantation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Pregnancy-Related Liver Disease. . . . . . . . . . . . . . . . . . . . 73 Vascular Diseases of the Liver . . . . . . . . . . . . . . . . . . . . . . 73 Portal Vein Thrombosis. . . . . . . . . . . . . . . . . . . . . . . . 73 Budd-Chiari Syndrome. . . . . . . . . . . . . . . . . . . . . . . . 74

Disorders of the Gallbladder and Bile Ducts Asymptomatic Gallstones. . . . . . . . . . . . . . . . . . . . . . . . . . Biliary Colic and Acute Cholecystitis . . . . . . . . . . . . . . . . Clinical Manifestations. . . . . . . . . . . . . . . . . . . . . . . . Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acalculous Cholecystitis. . . . . . . . . . . . . . . . . . . . . . . . . . .

74 74 74 74 74 75

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Common Bile Duct Stones and Cholangitis. . . . . . . . . . . 75 Gallbladder Cancer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Cholangiocarcinoma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Gastrointestinal Bleeding Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Upper Gastrointestinal Bleeding. . . . . . . . . . . . . . . . . . . . 76 Causes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Lower Gastrointestinal Bleeding. . . . . . . . . . . . . . . . . . . 80 Causes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Obscure Gastrointestinal Bleeding. . . . . . . . . . . . . . . . . . 82 Causes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Self-Assessment Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

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Gastroenterology and Hepatology Disorders of the Esophagus Symptoms of Esophageal Disorders Dysphagia Dysphagia is the awareness of food not passing during the swallowing process. The swallowing mechanism is made up of two distinct components: 1. The oropharyngeal process is the passage of the food bolus from the mouth into the hypopharynx and upper esophagus. 2. The esophageal process is the passage of the food bolus through the upper esophagus into the stomach. Patients typically describe a feeling of food “getting stuck” or being blocked while eating. Identifying which component of the swallowing process (oropharyngeal or esophageal) is abnormal is key for formulating the differential diagnosis and devising a diagnostic and management plan. There are many causes of dysphagia, which are described in Table 1.

Oropharyngeal Dysphagia Patients with oropharyngeal dysphagia (also known as transfer dysphagia) are unable to initiate the swallowing process despite several attempts to swallow. Patients typically describe coughing, choking, and nasal regurgitation. Choking occurs owing to failure to clear food from the epiglottis and may lead to aspiration. Oropharyngeal dysphagia often occurs within 1 second of starting the swallowing process. Recurrent episodes of pulmonary infections (including pneumonia) can be a result of chronic aspiration. Symptoms of underlying systemic neurologic disease include hoarseness (laryngeal nerve dysfunction) and dysarthria (weakness of the soft palate or pharyngeal constrictors). Regurgitation of undigested food hours after eating or reports of a gurgling noise in the neck are symptoms of Zenker diverticulum. The initial test of choice for evaluation of oropharyngeal dysphagia is a modified barium swallow, also known as videofluoroscopy. The test begins with a liquid phase, which is followed by a solid phase if the liquid phase is not diagnostic. If results of the modified barium swallow are normal, oropharyngeal dysphagia is excluded and further evaluation should focus on the possibility of esophageal dysphagia. Oropharyngeal forms of dysphagia are often managed with dietary adjustment and incorporation of swallowing exercises with the assistance of a speech pathologist.

Key Point

• The initial test of choice for evaluation of oropharyngeal dysphagia is a modified barium swallow, also known as videofluoroscopy.

Esophageal Dysphagia Patients with esophageal dysphagia often localize discomfort to the lower sternum and do not report problems initiating the swallowing process. Dysphagia to solid foods suggests mechanical obstruction; dysphagia to liquids or both solids and liquids suggests a motility disorder. Patients with achalasia describe regurgitation of nonacidic undigested food in combination with dysphagia to solids and liquids. Esophageal spasm is associated with chest pain that may be triggered by consuming liquids of extreme hot or cold temperatures. Systemic symptoms such as Raynaud phenomenon in the setting of heartburn suggest systemic sclerosis, a cause of both mechanical obstruction and motility disorders. Luminal causes of obstruction may include benign strictures, malignancy, esophageal webs, or a Schatzki ring (Figure 1). Upper endoscopy is the most appropriate test for esophageal dysphagia; it allows for both diagnostic intervention (biopsies and inspection) and therapeutic intervention (dilation). Treatment is guided by the underlying pathology causing the dysphagia, as discussed in later sections. Key Points

• Esophageal dysphagia to solid foods suggests mechanical obstruction; dysphagia to liquids or both solids and liquids suggests a motility disorder. • Upper endoscopy is the most appropriate test for esophageal dysphagia; it allows for both diagnostic intervention (biopsies and inspection) and therapeutic intervention (dilation).

Reflux and Chest Pain Reflux is the regurgitation of acidic contents from the stomach into the esophagus or back of the throat. Untreated reflux can lead to development of a peptic stricture, causing solid-food dysphagia. Pyrosis, also known as heartburn, is the most common digestive complaint in Western populations. Heartburn often occurs approximately 1 hour after eating and is temporarily relieved with antacids. Factors that can trigger or exacerbate reflux symptoms are listed in Table 2. Patients may have esophageal chest pain symptoms that are identical to those of cardiac chest pain. Esophageal chest 1

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Disorders of the Esophagus

Table 1.  Causes of Dysphagia Condition

Diagnostic Clues Oropharyngeal Dysphagia

Structural disorders Cervical osteophytes

High dysphagia, degenerative joint disease

Cricoid webs

High dysphagia, iron deficiency

Pharyngoesophageal (Zenker) diverticulum

Aspiration, neck mass, and regurgitation of foul-smelling food

Thyromegaly

Neck mass

Neurologic/myogenic disorders Amyotrophic lateral sclerosis

Upper and lower motoneuron signs, fasciculations

Central nervous system tumor

Headache, vision changes, nausea, seizures, balance problem

Stroke

Focal neurologic deficits

Muscular dystrophy

Slow progression of muscular weakness over years

Myasthenia gravis

Weakness with repetitive activity

Multiple sclerosis

Optic neuritis

Parkinson disease

Bradykinesia, rigidity, tremor

Dementia

Altered cognition

Sjögren syndrome

Dry mouth, dry eyes Esophageal Dysphagia

Structural disorders Dysphagia lusoria (vascular dysphagia)

Vascular extrinsic compression on the esophagus on imaging

Epiphrenic/traction diverticulum

Outpouching of the esophagus at any level on imaging

Esophageal strictures

Intermittent dysphagia, especially for solid food; history of reflux

Eosinophilic esophagitis

Food impactions, atopic history, rings or strictures on endoscopy

Esophageal webs or rings

Usually incidental finding, may be associated with iron deficiency anemia

Neoplasms

Rapidly progressive dysphagia for solids, then liquids; anorexia; weight loss

Motility disorders Achalasia

Concomitant liquid and solid dysphagia

Diffuse esophageal spasm

Chest pain

Systemic sclerosis

Tight skin, telangiectasias, sclerodactyly, GERD, Raynaud phenomenon

GERD = gastroesophageal reflux disease.

CONT.

pain may be induced by physical activity, similarly to cardiac chest pain. The most common cause of noncardiac chest pain is untreated gastroesophageal reflux disease (GERD), followed by motility disorders. Cardiac causes must be ruled out before chest pain is attributed to an esophageal cause. A trial of an acid-reducing agent such as a proton pump inhibitor (PPI) may alleviate symptoms, confirming the diagnosis of GERD. If symptoms are unresponsive to a PPI trial, additional evaluation with upper endoscopy, ambulatory pH testing, and/or esophageal manometry may be warranted. For diagnosis and management of reflux, see Gastroesophageal Reflux Disease. Key Point

• Cardiac causes must be ruled out before chest pain is attributed to an esophageal cause.

Odynophagia Odynophagia is defined as pain with swallowing and is an indication of inflammation in the esophagus. Odynophagia is a sign of mucosal injury of the esophagus leading to ulceration. The most common causes of odynophagia are caustic ingestion, pill-induced damage, and infection with Candida, herpesvirus, or cytomegalovirus. Rarely, it has been associated with severe GERD or esophageal cancer. Upper endoscopy is the diagnostic test of choice for visual inspection and obtaining tissue biopsies.

Globus Sensation Globus is the sensation of tightness or a lump in the throat. Globus occurs between swallows and is not related to meals. Stress, psychiatric disorders (anxiety, panic disorders,

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Disorders of the Esophagus

Table 2.  Factors Associated with Reflux Category

Factor

Lifestyle

Cigarette smoking Obesity

Eating habits

Eating large meals Eating late at night Lying supine shortly after eating

Foods and beverages

Alcohol Chocolate Citrus fruits and juices Coffee Fatty and fried foods Onions Peppermint

Medications

Anticholinergic agents Aspirin and NSAIDs Calcium channel blockers Nitrates Progesterone Opioids (due to delayed gastric emptying)

Body position

Bending over, exercising (both result in increased intra-abdominal pressure)

Other

Pregnancy Tight-fitting clothing Hiatal hernia

F i g u r e 1 . Barium esophagography showing a Schatzki ring.

somatization), and frequent dry swallowing have been associated with globus. Globus should not be diagnosed in the setting of dysphagia or odynophagia. The management of globus should include ruling out an underlying pharyngeal lesion by nasal endoscopy or barium swallow. If these studies are negative, treatment with acid suppression (PPI) or cognitive behavioral therapy should be considered. Globus has been associated with GERD.

Nonmalignant Disorders of the Esophagus Esophageal Motility Disorders The esophagus is the conduit between the hypopharynx and stomach. The tubular esophagus is composed of both skeletal muscle (upper third) and smooth muscle (lower two thirds). Nerve innervations for the striated component are axons of lower motoneurons. The smooth muscle portion of the esophagus is innervated by the vagus nerve. Primary peristalsis begins with swallowing and runs the entire length of the tubular esophagus. The upper and lower esophageal sphincters

relax during swallowing (Figure 2). Secondary peristaltic activity occurs when the esophagus is distended with air or fluid; peristalsis begins at the point of distention. Highresolution esophageal manometry is a valuable tool in evaluating esophageal physiology.

Hypertonic Motility Disorders Achalasia and Pseudoachalasia Achalasia is a motility disorder of the esophagus that results in aperistalsis and inadequate relaxation of the lower esophageal sphincter (LES). The cause of achalasia is unknown, but the pathophysiologic process involves ganglion cell and myenteric plexus degeneration in the esophageal body and LES. This nerve imbalance leads to uncontested action by cholinergic nerves and incomplete LES relaxation. It affects men and women equally, with an annual incidence of 1 in 100,000 individuals. It tends to occur between the ages of 30 and 60 years. The clinical presentation of achalasia consists of dysphagia to both solids and liquids along with regurgitation of undigested bland food and saliva. Patients may also experience weight loss, chest pain, and even heartburn, resulting in a misdiagnosis of GERD. Symptoms of true achalasia do not respond to an empiric trial of acid reducers such as PPIs. 3

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Each of the numbered items is followed by lettered answers. Select the ONE lettered answer that is BEST in each case.

Item 1 A 55-year-old man is evaluated during a routine examination. He feels well other than mild knee pain. He drinks six to eight cans of beer per night. He has no personal history of liver disease, but his older brother was recently diagnosed with hereditary hemochromatosis. On physical examination, vital signs are normal; BMI is 24. He is tanned on sun-exposed body surfaces. Cardiac examination is normal. Abdominal examination reveals hepatomegaly. Bilateral bony hypertrophy of the knees is noted. Laboratory studies: Alanine aminotransferase Aspartate aminotransferase Ferritin Transferrin saturation

70 U/L 160 U/L 592 ng/mL (592 µg/L) 40%

Genetic testing for hemochromatosis reveals heterozygosity for C282Y. Abdominal ultrasound reveals a change in liver echotexture consistent with fatty changes. Which of the following is the most appropriate treatment? (A) (B) (C) (D)

Administer deferoxamine Perform phlebotomy Repeat serum iron tests now Stop alcohol intake

Item 2 A 40-year-old man is evaluated for a 6-month history of intermittent episodes of two to four loose stools per day. When he has diarrhea, he also notices crampy abdominal pain and bloating. He has not had nausea, vomiting, anorexia, fever, melena, hematochezia, recent travel, or any new medications, including antibiotics. He is overweight but has been exercising and watching his diet for the past 6 months, and he has intentionally lost 6.8 kg (15.0 lb). The main change in his diet has been switching to diet soda and using sugar-free sweeteners. He takes no medications. On physical examination, vital signs are normal. The abdomen is obese but soft with normal bowel sounds and no distention or tenderness. Which of the following is the most appropriate management? (A) (B) (C) (D) (E)

Abdominal CT scan Colonoscopy with biopsies Discontinuation of sugar-free sweeteners Gluten-free diet Tissue transglutaminase IgA antibody testing

Item 3 A 68-year-old man is evaluated for new-onset ascites with lower-extremity edema. Symptoms have increased gradually over the past 4 weeks. He has consumed three alcoholic beverages per day for many years. His medical history is

notable for coronary artery bypass graft surgery 8 months ago and dyslipidemia. His medications are low-dose aspirin, atorvastatin, and metoprolol. On physical examination, temperature is 36.8 °C (98.2 °F), blood pressure is 122/84 mm Hg, pulse rate is 64/min, and respiration rate is 16/min; BMI is 28. Cardiac examination reveals an elevated jugular venous pressure, a normal S1 and S2, and no murmurs. Pulmonary examination findings are normal. Abdominal examination reveals hepatomegaly, distention, dullness to percussion over the flanks, and a positive fluid wave. There is 2+ pitting edema of the lower extremities. Laboratory studies reveal a serum albumin level of 3.5 g/dL (35 g/L). Other studies, including serum alanine aminotransferase and aspartate aminotransferase levels, are normal. Paracentesis reveals a total nucleated cell count of 120/µL with 30% polymorphonucleocytes. Ascitic fluid albumin level is 2.3 g/dL (23 g/L) and total protein is 3.5 g/ dL (35 g/L).

Self-Assessment Test

Directions

Which of the following is the most likely cause of this patient’s ascites? (A) (B) (C) (D)

Alcoholic cirrhosis Constrictive pericarditis Nonalcoholic cirrhosis Tuberculous peritonitis

Item 4 A 48-year-old woman is evaluated at an urgent care center for a 2-day history of severe retrosternal chest pain. She has not had heartburn or dysphagia. She is finishing a course of treatment for Lyme disease, but she has no other medical problems and otherwise feels well. Her only medication is doxycycline. Physical examination is unremarkable, and laboratory studies are normal. Which of the following is the most likely diagnosis? (A) (B) (C) (D)

Barrett esophagus Candida esophagitis Eosinophilic esophagitis Pill-induced esophagitis

Item 5 A 56-year-old woman is hospitalized for new-onset confusion. She has a history of decompensated hepatitis B cirrhosis with chronic ascites. Her medications are spironolactone, furosemide, lactulose, and entecavir. On physical examination, temperature is 36.8 °C (98.2 °F), blood pressure is 118/62 mm Hg, pulse rate is 88/ min, and respiration rate is 20/min; BMI is 23. She is disoriented to time and date. Asterixis is noted. The abdomen is moderately distended with ascites. Laboratory studies reveal a serum bilirubin level of 2.9 mg/dL (49.6 µmol/L), a serum creatinine level of 1.3 mg/dL 91

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Answers and Critiques Answer:

D

Item 2

Answer:

C

Educational Objective: Treat alcohol-induced liver disease with alcohol cessation.

Educational Objective: Manage chronic diarrhea caused by malabsorption of sugar-free sweeteners.

This patient has alcohol-induced liver disease, and the most appropriate treatment is to stop alcohol intake. In alcohol-induced liver disease, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels are typically elevated two to six times the upper limit of normal but AST levels above 500 U/L and ALT levels above 200 U/L are uncommon. An AST/ALT ratio above 2 to 3 is typical for alcoholic liver disease. Hereditary hemochromatosis is an autosomal recessive disease, and homozygosity for C282Y is generally required to cause iron overload. The initial step in evaluating patients with suspected hemochromatosis is a serum transferrin saturation measurement, which is the most sensitive test in diagnosing this condition. Elevated serum transferrin saturations suggest hemochromatosis, and further assessment is advised, usually with serum ferritin measurement and hemochromatosis gene testing. Serum ferritin, although not usually used as an initial diagnostic study for suspected hemochromatosis, is a surrogate measure of iron stores; values greater than 1000 ng/mL (1000 µg/L) in the absence of an inflammatory state or another cause for liver disease suggest hemochromatosis. Serum ferritin measurement is therefore used as a follow-up study for elevated transferrin saturation levels. A liver biopsy specimen stained for iron confirms tissue iron overload. This patient is heterozygous for C282Y and has a slightly elevated serum ferritin level but a normal transferrin saturation; these findings do not support the diagnosis of hemochromatosis. Isolated elevations of serum ferritin, as seen in this patient, can be due to inflammatory states such as liver injury from another cause, including alcohol-induced liver disease. Phlebotomy (the treatment of choice for hemochromatosis) and iron chelation with deferoxamine (the typical treatment for secondary iron overload conditions) are not necessary at this time. Repeating serum iron tests now will not add much useful information at this time; however, repeat testing should be performed later after the patient decreases his alcohol intake, as iron overload may result in some patients despite an absence of homozygosity for C282Y.

The most appropriate management is discontinuation of sugar-free sweeteners. The appearance of this patient’s diarrhea coincided with healthy lifestyle changes that include the ingestion of artificial sweeteners. The temporal association between the onset of this patient’s diarrhea and his dietary changes makes it highly likely that the exposure to nonabsorbable sugar alcohols (“sugar-free sweeteners”) is the cause of his symptoms. The presence of bloating is also characteristic of diarrhea due to nonabsorbed carbohydrates. In this patient, further testing is not necessary before recommending the discontinuation of sugar-free sweeteners. However, if the likely diagnosis was less clear, assessment of his stool electrolytes would be helpful. In diarrhea caused by malabsorbed carbohydrates, an elevation in the osmotic gap would be expected. The osmotic gap is calculated using the following equation:

Key Point

• Isolated elevations of serum ferritin levels can be due to inflammatory states such as liver injury from another cause, including alcohol-induced liver disease.

Bibliography Adams PC. Evaluation of cirrhosis with an elevated ferritin. Clin Gastroenterol Hepatol. 2012 Apr;10(4):368-70. [PMID: 22037432]

Answers and Critiques

Item 1

290 – 2 × [stool sodium + stool potassium] A gap greater than 100 mOsm/kg (100 mmol/kg) indicates an osmotic diarrhea. If the gap is less than 50 mOsm/ kg (50 mmol/kg), the diarrhea is not osmotic. A gap between 50 and 100 mOsm/kg (50 and 100 mmol/kg) is equivocal. Sugar-free sweeteners are metabolized by gut bacteria, liberating gas and osmotically active substances that cause diarrhea and account for the osmotic gap. Pancreatic cancer could present with diarrhea and weight loss, but this patient’s age, absence of abdominal pain, and correlation of symptoms with dietary changes make this diagnosis less likely. Therefore, a CT scan should be deferred until a dietary cause of his symptoms is excluded. Patients with microscopic colitis lack signs of systemic inflammation and present with painless watery diarrhea without bleeding. Diagnosis can only be made when biopsies of the colon show a predominance of intraepithelial lymphocytes in the colonic mucosa (lymphocytic colitis) or the addition of a thickened subepithelial collagen band (collagenous colitis). Colonoscopy with biopsies would be useful to exclude microscopic colitis, but this diagnosis is uncommon in younger males and would not cause an osmotic diarrhea. Celiac disease is thought to affect nearly 0.5% to 1% of individuals in the United States. The typical features of celiac disease are diarrhea, bloating, and weight loss. Tissue transglutaminase (tTG) IgA antibody measurement would be useful to evaluate for celiac disease, but this patient’s symptoms began after a dietary change, making celiac disease unlikely. In addition, the empiric use of a gluten-free diet is not recommended in the absence of a confirmed diagnosis of celiac disease. 113

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MKSAP 17 - Gastroenterology and Hepatology  

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