Typically, symptoms that may indicate the presence of an esophageal disorder include heartburn, dysphagia, odynophagia, and regurgitation. Endoscopy is the technique of choice to evaluate the mucosa of the esophagus and to detect structural abnormalities, whereas esophageal manometry is the standard test to diagnose motor disorders of the esophageal body and the lower esophageal sphincter. This review examines normal esophageal anatomy and physiology, the diagnosis of esophageal disorders, disease states causing dysphagia, and gastroesophageal reflux disease. Figures show the cross-sectional anatomy of the esophagus; an algorithm for the evaluation of dysphagia; the anatomy of the gastroesophageal junction; esophagograms of patients with achalasia, late-stage achalasia, and diffuse esophageal spasm; endoscopic views of esophageal strictures; a proximal esophageal web on barium swallow in a patient with Plummer-Vinson syndrome; an endoscopic view of the esophagus of a 25-year-old man with a 3-year history of severe dysphagia; photographs of midesophageal traction diverticulum, multiple epiphrenic diverticula, long-segment Barrett esophagus, and severe Candida esophagitis; and a treatment algorithm for extraesophageal manifestations of gastroesophageal reflux disease. Tables list the high-resolution manometry classification of esophageal motility disorders, causes of esophageal strictures, classic endoscopic findings in patients with eosinophilic esophagitis, the Los Angeles classification of erosive esophagitis, categories of dysplasia, surveillance of Barrett metaplasia, medications implicated in pill-induced esophagitis, and classification of caustic esophageal injury.

This review contains 13 figures, 40 tables, and 82 references

Keywords: achalasia, dysphagia, esophagus, reflux, strictures, diverticula, endoscopy, larynx

Colonic diverticula are herniations of colonic mucosa and submucosa through the muscularis propria. They occur where perforating arteries traverse the circular muscle layer, in parallel rows between the mesenteric and antimesenteric taenia. Colonic diverticular disease may present as diverticulosis, diverticulitis, or diverticular bleeding. Of patients with known diverticulosis, only 10% to 20% will develop diverticulitis. Diverticulitis varies in presentation and severity. This chapter discusses the diagnosis, differential diagnosis, and management of diverticulitis and its complications. Appendicitis is generally caused by obstruction of the lumen of the appendix, followed by infection. In the United States, the lifetime risk of appendicitis is about 9% for males and 7% for females. This chapter also discusses the diagnosis of appendicitis (including typical and atypical presentations and appendicitis as it presents in special groups of patients) and its management.

This review contains 3 figures, 21 tables, and 76 references.

Keywords: Diverticulosis, diverticulitis, gastrointestinal bleeding, appendicitis, abdominal infection, appendiceal perforation, antibiotics, appendectomy, colectomy, laparoscopy

Acute pancreatitis is characterized by an acute inflamatory process of the pancreas associated with abdominal pain and elevations in serum levels of pancreatic enzymes. The acute inflammation usually completely resolves with restoration of normal pancreatic architecture and function. By contrast, chronic pancreatitis is characterized by the presence of ongoing inflammation and irreversible damage to the gland. Recurrent attacks of acute pancreatitis may lead to chronic pancreatitis over time. This chapter discusses the epidemiology, etiology, pathogenesis, diagnosis, and treatment of acute and chronic pancreatitis. Figures illustrate findings on imaging studies in patients with pancreatic disorders. 

This review contains 6 figures, 25 tables, and 86 references.

Keywords: Acute pancreatitis, chronic pancreatitis, pseudocyst, exocrine insufficiency, endocrine insufficiency, magnetic retrograde cholangiopancreatography, endoscopic ultrasonography

Gallstones (cholelithiasis) are hardened deposits of digestive fluid that can form in the gallbladder and bile ducts. Gallstones range in size from as small as a grain of sand to as large as a billiard ball. Some people develop a single gallstone, whereas others develop many. Gallstone disease or disorders may encompass biliary pain, acute and chronic cholecystitis, choledocholithiasis, and gallstone pancreatitis. Gallstones (cholelithiasis) and biliary tract diseases constitute a common and costly health problem in the United States. This chapter reviews the formation of the two principal types of stone, the cholesterol stone and the pigment stone, that form in the gallbladder and biliary tract. The prevention of gallstones is discussed. The diagnosis, differential diagnosis, treatment, and complications of acute cholecystitis are presented. Diagnosis and treatment of chronic cholecystitis, asymptomatic cholelithiasis, choledocholithiasis, Mirizzi syndrome, and gallbladder polyps are also discussed. Common bile duct stricture, primary sclerosing cholangitis, recurrent pyogenic cholangitis, choledochal cyst, and sphincter of Oddi dysfunction are summarized. 

This review contains 6 figures, 19 tables, and 111 references. 

Keywords: Gallbladder, gallstones, cholecystectomy, biliary sludge, cholangitis, choledocholithiasis, cholecystitis, endoscopic retrograde cholangiopancreatography

The overall incidence of gastric carcinoma has decreased in the past few decades, but it remains the second leading cause of cancer death worldwide. Malignant tumors of the small intestine are rare, and account for fewer than 5% of all gastrointestinal tract malignancies. This review details the classification, risk factors, clinical evaluation, investigative studies, staging, management, and follow-up and management of recurrent disease in gastric adenocarcinoma; in addition, it examines nonadenocarcinomatous gastric malignancies and small bowel malignancies. 

This review contains 7 figures, 21 tables, and 97 references.

Keywords:Gastric adenocarcinoma, gastrointestinal stromal tumor, gastric lymphoma, Helicobacter pylori, small bowel adenocarcinoma, surgical resection, staging, chemotherapy, radiation therapy

Hernia is defined as an abnormal protrusion of an organ or tissue through a pathologic defect in its surrounding wall. Overall, hernia is common and is generally believed to be a benign condition associated with some morbidity, although it is not thought to be associated with significant mortality. Between 2001 and 2010, 2.3 million inpatient abdominal hernia repairs were performed in the United States, of which 567,000 were performed emergently. In some cases, a hernia can be a deadly condition. In 2002, hernia was listed as the cause of death for 1,595 US citizens. This review covers the pathophysiology, stabilization and assessment, diagnosis and treatment, and disposition and outcomes of hernia. Figures show anatomic locations of the various abdominal wall, groin, lumbar, and pelvic floor hernias; a direct inguinal hernia; an indirect inguinal hernia; point-of-care sonograms showing a ventral wall hernia and an abdominal wall hernia; and the differential diagnosis of an abdominal mass based on anatomic location. Tables list risk factors for the development of inguinal hernia, sex-based differences in inguinal hernia development, risk factors for the development of incisional hernia, factors to consider when assessing the patient for a hernia, and factors associated with the highest rates of incarceration in patients with groin hernia.

Key words: emergent hernia, hernia incarceration, incisional hernia, inguinal hernia, strangulated hernia

This review contains 6 highly rendered figures, 5 tables, and 66 references.

Inflammatory bowel disease (IBD) encompasses both ulcerative colitis and Crohn disease, and is characterized by recurrent bouts of inflammation of the gastrointestinal tract. IBD affects approximately 4 million people worldwide, and rates are gradually increasing. This review covers the etiology, epidemiology, definition and pathophysiology, extraintestinal manifestations, and other disease-related complications of IBD. Figures show the distribution of ulcerative colitis and Crohn disease by location, several colonoscopic photographs of patients with ulcerative colitis as well as those with Crohn disease, computed tomography images of patients with Crohn disease, small bowel follow-through and fluoroscopic spot images of a patient with chronic structuring Crohn disease, and a computed tomographic scan showing extraenteric manifestations of Crohn disease. Tables list the differential diagnosis of ulcerative colitis, types of infectious colitis, complications of IBD, diagnostic criteria of toxic colitis, physical signs of Crohn disease, differences between Crohn disease and ulcerative colitis, and common extraintestinal manifestations of IBD.

This review contains 11 highly rendered figures, 7 tables, and 63 references.

There have been considerable advances in the treatment of inflammatory bowel disease (IBD) since the 20^th century, and there are multiple options available to the clinician. The management of IBD depends on the location of disease, as well as its clinical, endoscopic and histologic severity. The field is currently undergoing a paradigm shift from a step-up approach (starting treatment with a “milder” medication and, if this treatment fails, moving on to a more powerful medication) to a top-down approach (in which stronger medications are given earlier in the disease course). This review details the medications used to treat IBD, nutrition in IBD patients, and surgical treatment of IBD. Figures show step-up therapy, top-down therapy, strictureplasty technique, gross pathology image of a patient with Crohn disease and previous ileocecal resection, and ileal pouch anal anastomosis surgery. Tables list 5-aminosalicylic acid medications, antibiotics, corticosteroids, immunomodulators, and biologic medications used to treat IBD, as well as causes of nutritional deficiencies in IBD patients.

This review contains 5 highly rendered figures, 6 tables, and 96 references.

Peptic ulcers are defects or breaks in the inner lining of the gastrointestinal (GI) tract. Although the pathogenesis is multifactorial they tend to arise when there is an imbalance between protective and aggressive factors, such as when GI mucosal defense mechanisms are impaired in the presence of gastric acid and pepsin. Peptic ulcers extend through the mucosa and the muscularis mucosae, a thin layer of smooth muscle separating the mucosa from the deeper submucosa, muscularis propria, and serosa. Peptic ulcer disease affects up to 10% of men and 4% of women in Western countries at some time in their lives. This chapter discusses the pathogenesis of peptic ulcer disease and the etiologic contribution of Helicobacter pylori infection, nonsteroidal anti-inflammatory drugs, and gastrinoma or other hypersecretory states. Also addressed are rare and unusual causes for ulcers and GI bleeding. A section on the diagnosis of peptic ulcers discusses clinical manifestations, physical examination findings, laboratory and imaging studies, and surgical diagnosis. Differential diagnosis is also reviewed. Tests to establish the etiology of peptic ulcer disease include endoscopy, quantitative serologic tests, the urea breath test, and the fecal antigen test. Discussed separately are treatments for uncomplicated duodenal ulcers, uncomplicated gastric ulcers, intractable duodenal or gastric ulcers, complicated peptic ulcers (bleeding ulcers, acute stress ulcers, perforated ulcers, obstructing ulcers, fistulizing ulcers, and Cameron ulcers), H. pylori ulcers, and gastric cancer. Figures illustrate the etiopathogenesis of peptic ulcers, prevalence of H. pylori infection in duodenal and gastric ulcer patients compared with normal controls, the approach to a patient with new and undiagnosed ulcerlike symptoms refractory to antisecretory therapy, an upper GI series showing an uncomplicated duodenal ulcer, a chest x-ray showing pneumoperitoneum from a perforated duodenal ulcer, gastric biopsy samples showing H. pylori organisms, and the approach to treatment and follow-up in patients with either complicated or uncomplicated duodenal or gastric ulcer. Tables list differential diagnoses of peptic ulcer disease, commonly used regimens to eradicate H. pylori, additional antimicrobial agents with activity against H. pylori, and FDA-approved antisecretory drugs for active peptic ulcer disease.

This chapter contains 5 figures, 6 tables and 78 references.

Gastrointestinal (GI) motility disorders represent diseases characterized by abnormal, predominantly impaired, sometimes exaggerated, movement of contents through the GI tract due to neuromuscular dysfunctions in the absence of mucosal disease and mechanical causes of impaired passage. By contrast, functional GI disorders represent illnesses, defined only by GI symptoms, which occur in the absence of mucosal or structural abnormality or of known biochemical or metabolic disorders. The first section of this chapter discusses the enteric and extrinsic neural regulation of GI sensorimotor functions and normal GI motility in humans. Disorders such as gastroparesis (including diabetic gastroparesis, idiopathic gastroparesis, and postsurgical gastroparesis), dumping syndrome, intestinal pseudo-obstruction, small intestinal bacterial overgrowth, megacolon (including Hirschsprung disease, toxic megacolon, and colonic pseudo-obstruction), chronic constipation (including defecatory disorders, normal transit constipation, and slow transit constipation), functional dyspepsia, functional diarrhea and irritable bowel syndrome, and fecal incontinence are then discussed in depth. Tables present a comparison of GI motility and functional disorders, the causes of gastroparesis, the etiology of intestinal pseudo-obstruction and fecal incontinence, common medical conditions and medications associated with constipation, and the symptom severity scale in fecal incontinence. Illustrations, graphs, magnetic resonance images, and algorithms are provided.
This chapter contains 10 highly rendered figures, 6 tables, 92 references, and 5 MCQs.

Irritable bowel syndrome (IBS) is a complex, functional gastrointestinal condition characterized by abdominal pain and alteration in bowel habits without an organic cause. One of the subcategories of this disorder is IBS with diarrhea (IBS-D). Clinically, patients who present with more than 3 months of abdominal pain or discomfort associated with an increase in stool frequency and/or loose stool form are defined as having IBS-D. This review addresses IBS-D, detailing the epidemiology, etiology and genetics, pathophysiology and pathogenesis, diagnosis, clinical manifestations and physical examination findings, differential diagnosis, treatment, emerging therapies, complications, and prognosis. Figures show potential mechanisms and pathophysiology of IBS, IBS-D suspected by clinical assessment and Rome III criteria, pharmacologic and nonpharmacologic treatment options, potential mechanisms of action of probiotics, and potential treatment modalities. Tables list the Rome criteria for IBS, alarm signs and symptoms suggestive of alternative diagnoses, IBS criteria, differential diagnosis of IBS-D, dietary advice options for IBS-D, and alternative and emerging therapies in IBS-D.

This review contains 5 highly rendered figures, 6 tables, and 99 references. 

This review presents an overview of the management of constipation. The review addresses the diagnosis of primary and secondary forms and then discusses in greater detail the investigative workup and modern management of chronic constipation (primary). The review addresses what simple and more advanced investigations are relevant for determining pathophysiology and gives an overview of treatment options, including pharmacologic, behavioral, and surgical approaches for thus defined subgroups of patients (evacuation disorder, slow transit constipation).

This review contains 3 figures, 6 tables, and 89 references.

Gastrointestinal bleeding occurs when a pathologic process such as ulceration, inflammation, or neoplasia leads to erosion of a blood vessel. Bleeding can occur in the upper gastrointestinal tract (50%) or the lower gastrointestinal tract (40%) or may be obscure (10%), meaning that no definitive source is identified. Gastrointestinal bleeding is common, with major bleeding leading to 1 million hospitalizations every year in the United States. This review details the pathophysiology of gastrointestinal bleeding and the stabilization and assessment, diagnosis, treatment, and disposition and outcomes of patients with gastrointestinal bleeding. Situations requiring special consideration are also discussed. Figures show how gastrointestinal bleeding occurs when a pathologic process causes erosion of the mucosa and exposes a submucosal blood vessel; an ulcer with a raised, red, variceal spot; a Mallory-Weiss tear; the formation of varices; vascular ectasia; treatment of esophageal varices with balloon tamponade; and a wireless capsule. Tables list the major causes of gastrointestinal bleeding, terms relating to gastrointestinal bleeding and their definitions, Blatchford score, substances that interfere with occult blood testing, clinical factors differentiating gastrointestinal bleeding placed in descending order of likelihood ratio, and a summary of American College of Radiology recommendations for angiography in nonvariceal gastrointestinal bleeding.

This review contains 8 figures, 15 tables, and 107 references.

Key Words: gastrointestinal bleeding, inflammation, occult blood testing, UGIB, LGIB, Blatchford score, angiography, wireless capsule endoscopy (WCE)

Gastrointestinal infections, which present with acute diarrhea, sometimes accompanied by vomiting, are an extremely common medical complaint, with an annual incidence of 0.6 illnesses per person. Transmission can occur from animals to person, from person to person, or by the ingestion of contaminated foodstuffs. In the United States, more than 90% of cases are caused by viruses, with norovirus being by far the most common. Common among bacterial causes of acute gastrointestinal infection are Salmonella, Campylobacter, Shigella, Shiga toxin–producing Escherichia coli, Vibrio,Yersinia, and Clostridium difficile. These infections are typically self-limited, but depending on the etiologic agent and characteristics of the host, antibiotic therapy may be indicated. Certain gastrointestinal infections are associated with significant complications, including reactive arthritis, Guillain-Barré syndrome, or septicemia.

This review contains 4 figures, 7 tables, and 60 references.

Key words: Campylobacter, Escherichia coli, Guillain-Barré syndrome,reactive arthritis, Shiga toxin, Shigella, Vibrio, Yersinia

Inflammatory bowel diseases (IBDs) are complex disorders that develop in genetically susceptible hosts due to dysregulated immune responses to microbial dysbiosis and environmental changes. Although in the vast majority of cases, the genetic contribution to development of these diseases is small, in rare cases, IBD develops directly as a result of deleterious mutations in the genes involved in immune and epithelial cell function. In these cases, intestinal inflammation is usually severe, which develops in most cases in the first years of life and occasionally is accompanied by recurrent or atypical infections. In this review, the approach to different monogenic disorders that cause IBD is discussed, including mutations in the IL-10 pathway, neutrophil defects, regulatory T-cell disorders, autoinflammatory conditions, epithelial cell diseases, and disorders affecting B- and T-lymphocyte dysfunction. Moreover, a multidisciplinary diagnostic approach is suggested, which highlights in which cases a monogenic disorder should be suspected.

This review contains 3 figures, 3 tables, and 42 references.

Key Words: inflammatory bowel disease, IL-10, chronic granulomatous disease, common variable immune deficiency, epithelial cells, genetics, immune cells, mucosal homeostasis, pathogenesis, very early–onset disease.

Heart failure is a devastating progressive disease process that is rising in incidence throughout the world. For patients with end-stage heart failure, orthotopic heart transplantation had been the only therapeutic option. Unfortunately, the number of patients requiring such therapy far exceeds the number of available organs. Recent advancements in technology have made implantable cardiac assist devices a reality. Outcomes with these devices are superior to maximal medical therapy and may serve either as a bridge to the availability of a donor organ or as “destination” therapy for the patient with end-stage heart failure. In addition, new technology can also provide temporary mechanical support for patients with acute decompensated cardiogenic shock, allowing preservation of end-organ function until more definitive long-term mechanical support can be coordinated. Patients with end-stage heart failure experience unique nutritional challenges. Mechanical circulatory support adds yet another unique dimension to the nutritional support challenges of this patient population.

This review contains 2 figures, 5 tables, and 29 references.

Key words: cardiogenic shock, enteral nutrition, extracorporeal membrane oxygenation, heart failure, mechanical circulatory support, nutritional support, parenteral nutrition, ventricular assist device

Malabsorption refers to the impaired intestinal absorption of nutrients. It can result from congenital defects in absorption and the transport of ions and nutrients, defects in hydrolysis within the intestinal lumen, acquired defects in the intestinal absorptive cells that line the surface of the intestine, impaired bile production, or interruption of enterohepatic circulation or secondary to pancreatic insufficiency. Maldigestion, another factor in nutrient absorption, refers to the impaired digestion of nutrients within the intestinal lumen or at the terminal digestive site of the brush border membrane of mucosal epithelial cells. Although malabsorption and maldigestion are pathophysiologically distinct, they are interdependent, and in clinical practice, malabsorption has come to signify derangements in either or both processes. This chapter discusses the clinical manifestations of malabsorption and tests for suspected malabsorption. The diseases that can cause malabsorption, their diagnosis, and treatment recommendations are included. Figures illustrate the diagnosis and management of celiac disease; an approach to gluten challenge for the diagnosis or exclusion of celiac disease in patients maintained on a gluten-free diet without previous definitive diagnostic testing; and the histologic features of celiac disease, Crohn disease, collagenous sprue, autoimmune enteropathy, eosinophilic gastritis, and intestinal lymphangiectasia. 

This review contains 9 figures, 25 tables, and 116 references.

Keywords: Malabsorption, maldigestion, Crohn disease, celiac disease, tropical sprue, diarrhea, endoscopy, short bowel syndrome, bacterial overgrowth

Irritable bowel syndrome (IBS) is characterized by recurrent abdominal pain or discomfort that has occurred at least 3 days per month in the 3 months prior to diagnosis. One of the subtypes of this disorder is IBS with constipation (IBS-C), where individuals experience hard or lumpy stools at least 25% of the time and loose or watery stools less than 25% of the time with defecation. This review addresses IBS-C, detailing the epidemiology, etiology, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, and prognosis. A figure shows the Bristol stool form scale. Tables list IBS subtypes, components of digital rectal examination, differential diagnoses for IBS and IBS-C, alarm features, and the American College of Gastroenterology Recommendations.

This review contains 1 highly rendered figure, 6 tables, and 71 references. 

Enteral nutrition (EN) is recognized as a medical nutrition therapy for patients with a functional gastrointestinal tract who are unable to maintain their weight and health by oral intake alone either due to a highly catabolic medical condition or a functional limitation. EN support provides calories and protein to help improve or maintain adequate weight, lean body mass, and overall nutritional status. EN also provides nonnutritive benefits such as maintaining intestinal integrity, supporting the immune system, and preventing infection. EN support can be tailored to a patient’s nutrient needs, and there are various formulas that vary in composition of macronutrients, concentration, and electrolytes for specific disease processes or conditions that may help with tolerance and absorption. EN support complications include issues with access, diarrhea, constipation, electrolyte abnormalities, hyperglycemia, and dehydration/overhydration. Generally, EN is well tolerated. While a patient is on this type of nutrition support, it is important to closely monitor tolerance, weight, laboratory values if indicated, and overall clinical progress, with adjustment to the regimen as needed.

This review contains 1 figure, 4 tables, and 48 references.

Key words: enteral access, enteral formula, enteral nutrition support, gastric residuals, gastrointestinal tract, immunonutrition, malnutrition, medical nutrition therapy, tube feed formula, tube feed tolerance, tube feeding, volume-based feeding

Bowel obstruction (mechanical and functional) is a common cause of hospitalization for abdominal pain; patients with complaints of abdominal pain, nausea, vomiting, distention, and lack of flatus or bowel movement should be evaluated for obstruction. The surgeon must approach this diagnosis in a stepwise fashion to determine whether the patient has ischemia necessitating emergent operative intervention or whether initial nonoperative management is warranted. Mechanical obstruction in the small bowel is most commonly caused by adhesions from previous surgery, hernia, or mass, whereas mechanical obstruction in the colon is most often caused by volvulus, cancer, and diverticular stricture. Initial evaluation includes a detailed history, physical examination, and biochemical evaluation with initiation of resuscitative efforts as needed. CT with intravenous contrast is often most readily available and most helpful in diagnosing bowel obstruction type; specific CT findings can suggest the need for urgent operative intervention. Water-soluble contrast medium challenge has emerged as an important adjunct in evaluating the likelihood that a patient with nonischemic bowel obstruction will require operative intervention.  

This review contains 14 figures, 15 tables and 65 references

Keywords:Adhesive bowel obstruction, ileus, ischemic bowel obstruction, laparoscopic adhesiolysis, large bowel obstruction, postoperative bowel obstruction, small bowel obstruction, volvulus, water-soluble contrast medium

There are multiple diseases of the stomach and esophagus that will lead a patient to seek emergent care, including peptic ulcer disease (PUD), esophagitis, dysphagia, esophageal foreign bodies, and gastroesophageal reflux disease (GERD). Hemorrhage and perforation are major emergencies in peptic ulcer disease and esophageal disease requiring early recognition with immediate resuscitative efforts to stabilize. This review covers the risk factors, pathophysiology, assessment and stabilization, diagnosis and treatment, and disposition and outcomes for patients with diseases of the stomach and esophagus. Figures show illustrations of esophageal anatomy, an algorithm for the evaluation of dysphagia, the pathogenesis of peptic ulcers, and radiographs demonstrating an esophageal button battery and pneumoperitoneum caused by a perforated ulcer. Tables list some common causes of esophageal stricture and pill-induced esophagitis, differential diagnosis of peptic ulcer disease and commonly used regimens to eradicate Helicobacter pylori infection.

Key Words: Peptic ulcer disease, esophagitis, dysphagia, esophageal foreign body, GERD, H. Pylori, button battery

Appendicitis is defined as inflammation of the vermiform appendix. It is the most common abdominal surgical emergency and occurs at an annual rate of approximately one in 10,000 in the United States. The lifetime risk of appendicitis is about 9% for males and 7% for females; approximately 80% of cases occur before 45 years of age. Appendicitis rarely occurs in infants; it increases in frequency between 2 and 4 years of age and reaches a peak between the ages of 10 and 19 years. However, clinicians must maintain a high index of suspicion in patients of all age groups. This review covers the pathophysiology, stabilization and assessment, and diagnosis and treatment of complicated and uncomplicated appendicitis. The disposition and outcomes are also reviewed. Figures show an image of appendicitis on a bedside sonogram, and a computed tomographic image of appendicitis. Tables list likelihood ratios of signs and symptoms of appendicitis, the sonographic appearance of appendicitis, the Alvarado scoring system, and the differential diagnosis of appendicitis.

 This review contains 2 figures, 7 tables, and 36 references.

Key words: appendicitis, obstructed appendiceal lumen, rebound abdomen, right lower quadrant pain, ruptured appendix

Abdominal pain is the most common presenting complaint in the emergency department (ED), accounting for nearly 8% of ED visits. Although many chronic conditions may cause pain in the abdomen, acute abdominal pain, defined as undiagnosed pain present for less than 1 week, is of greatest concern to the emergency practitioner. For many reasons, acute abdominal pain is often diagnostically challenging. Abdominal pain may be due to numerous causes, including gastrointestinal, genitourinary, cardiovascular, pulmonary, and other sources. Symptoms may fluctuate or change in nature, and the quality of pain can be difficult for the patient to describe. Physical examination findings, although important, are variable and can even be misleading. Despite being such a common presenting complaint, misdiagnosis is not uncommon and results in a high percentage of medicolegal actions in both and adult and pediatric populations.

This review contains 5 figures, 8 tables, and 92 references

Key words: abdominal computed tomography, abdominal pain, abdominal ultrasonography, pain management, point-of-care ultrasonography

Gastroesophageal reflux disease (GERD) is the most common gastrointestinal diagnosis made in outpatient clinics, responsible for over 5 million annual outpatient visits and likely hundreds of thousands of inpatient stays for noncardiac chest pain. GERD’s current definition, based on international consensus, is a “condition which develops when the reflux of stomach contents causes troublesome symptoms (i.e., at least two heartburn episodes per week) and/or complications.” Also defining GERD is the presence of erosive esophagitis on upper endoscopy (esophagogastroduodenoscopy [EGD]) with or without the presence of troublesome symptoms or the presence of troublesome symptoms without endoscopic evidence of erosive esophagitis (also known as nonerosive reflux disease). This review looks at GERD in detail, including its epidemiology and risk factors, genetics, pathogenesis and etiologic factors, clinical presentation and symptoms, differentials, diagnosis, and complications. Figures presented are an EGD image showing signs of erosive esophagitis, Barrett esophagus, and hiatal hernia and sample recordings from a 24-hour combined multichannel intraluminal impedance and pH testing. Tables list differential diagnoses for GERD, indications for performing EGD in patients with GERD symptoms, and a summary of GERD therapies.

This review contains ­2 figures, 4 tables, and 74 references. 

Acute mesenteric ischemia is interruption of intestinal blood flow by embolism, thrombosis, or a low-flow state. Bowel infarction is the end result of a process initiated by mediator release and inflammation. On clinical assessment, the early hallmark is severe abdominal pain but minimal physical findings. The abdomen remains soft, with little or no tenderness. Mild tachycardia may be present. Early diagnosis is difficult, but selective mesenteric angiography and computed tomographic angiography have the most sensitivity; other imaging studies and serum markers can show abnormalities but lack sensitivity and specificity early in the course of the disease, when diagnosis is most critical. Treatment is by embolectomy, anticoagulation, revascularization of viable segments, or resection; sometimes vasodilator therapy is successful. If diagnosis and treatment take place before infarction occurs, mortality is low; after intestinal infarction, mortality approaches 30 to 70%. For this reason, in the emergency department, clinical diagnosis should supersede diagnostic tests, which may delay treatment.

This review contains 6 figures, 4 tables and 40 references

Key words: acute mesenteric ischemia; bowel necrosis; chronic mesenteric ischemia; mesenteric occlusive disease; mesenteric venous thrombosis; nonocclusive mesenteric ischemia; postprandial abdominal pain; superior mesenteric artery thromboembolism

Of patients who present with major gastrointestinal (GI) bleeding, 20 to 30% will ultimately be diagnosed with bleeding originating from a lower GI source. Lower GI bleeding has traditionally been defined as bleeding originating from a source distal to the ligament of Treitz; however, with the advent of capsule endoscopy and deep enteroscopy allowing for visualization of the entire small bowel, the definition has been updated to GI bleeding originating from a source distal to the ileocecal valve. Lower GI bleeding can range from occult blood loss to massive bleeding with hemodynamic instability and predominantly affects older individuals, with a mean age at presentation of 63 to 77 years. Comorbid illness, which is a risk factor for mortality from GI bleeding, is also more common with increasing age. Most deaths related to GI bleeding are not due to uncontrolled hemorrhage but exacerbation of underlying comorbidities or nosocomial complications. This review covers the following areas: evaluation of lower GI bleeding (including physical examination and diagnostic tests), initial management, and differential diagnosis. Disorders addressed in the differential diagnosis include diverticulosis, arteriovenous malformations (AVMs), ischemic colitis, anorectal disorders, radiation proctitis, postpolypectomy bleeding, and colorectal neoplasms. Figures show an algorithm for management of patients with suspected lower GI bleeding, tagged red blood cell scans, diverticular bleeding, colonic AVM, ischemic colitis, bleeding hemorrhoid, chronic radiation proctitis, and ileocolonic valve polyp. Tables list descriptive terms for rectal bleeding and suggested location of bleeding, imaging modalities and differential diagnosis for lower GI bleeding, endoscopic techniques for hemostasis, and an internal hemorrhoids grading system.

This review contains 9 figures, 8 tables, and 103 references.

Gastrointestinal (GI) bleeding that is proximal to the ligament of Treitz is considered upper GI bleeding (UGIB). UGIB can be further divided into variceal and nonvariceal, differentiated by etiology, presentation, management, and mortality. This review of nonvariceal UGIB addresses the epidemiology, diagnosis, treatment (including endoscopic therapy), prognosis, and differential diagnosis. Recommendations presented are evidence based and consistent with consensus statements and society guidelines. Figures show stigmata of recent hemorrhage, endoscopic therapy, peptic ulcer disease, Mallory-Weiss syndrome, angiodysplasia, Dieulafoy lesion, and arterioenteric fistula. Tables list the manifestation of GI bleeding and the presumed source of the bleeding, clues in the symptom and presentation of the patient that may suggest the diagnosis, medical history and physical examination findings that can suggest a specific diagnosis, a comparison of different prognostic scoring systems, differential diagnosis of UGIB, various etiologies of peptic ulcer disease, and treatment regimens for Helicobacter pylori.

This review contains 7 figures, 10 tables, and 85 references