Porth's Essentials of Pathophysiology, 4e

astrointestinal disorders are not cited as the leading cause of death in developed countries of the world, nor do they receive the same publicity as heart disease and cancer. However, digestive diseases rank high in the total economic burden of illness, resulting in consider- able human suffering, personal expenditures for treat- ment, and lost working hours, as well as a drain on the nation’s economy. In 2004 alone, digestive disorders accounted for an estimated 72 million ambulatory visits in the United States. 1 Visits were common for all age groups, with the highest rate among persons 65 years and older. Even more important is the fact that proper nutrition or a change in health practices could prevent or minimize many of these disorders. Disruption in structure and function can occur at any level of the gastrointestinal tract, from the esophagus to the colon and rectum. This chapter is divided into three sections: (1) disorders of the esophagus, (2) disorders of the stomach, and (3) disorders of the small and large intestines. Disorders of the hepatobiliary system and exocrine pancreas are presented in Chapter 30. Disorders of the Esophagus The esophagus is a fixed muscular tube through which swallowed food and liquids pass as they move from the pharynx to the stomach. It lies posterior to the trachea and larynx and extends through the mediastinum, inter- secting the diaphragm at the level of the T11 or T12 ver- tebra. 2 The wall of the esophagus is lined with a mucosal layer of abrasion-resistant nonkeratinized stratified epi- thelium; its submucosal layer contains mucus-secreting glands that produce a lubricating fluid that protects its mucosal surface and aids in the passage of food; and its muscularis layer provides the peristaltic movements needed to propel food along its length. There are sphincters at either end of the esophagus: an upper esophageal, or pharyngoesophageal, sphincter that prevents reflux into the pharynx from the esoph- agus, and a lower esophageal, or gastroesophageal, sphincter that prevents reflux into the esophagus from Disorders of Gastrointestinal Function 29 C h a p t e r G

Disorders of the Esophagus Disorders of Esophageal Structure and Function

Swallowing Disorders Esophageal Diverticula Esophageal Lacerations Hiatal Hernia Gastroesophageal Reflux

Gastroesophageal Reflux Disease Gastroesophageal Reflux in Children Cancer of the Esophagus Disorders of the Stomach Gastric Mucosal Barrier Gastritis Acute Gastritis Chronic Gastritis Ulcerative Disorders Peptic Ulcer Disease Zollinger-Ellison Syndrome Stress Ulcers Cancer of the Stomach Disorders of the Small and Large Intestines Irritable Bowel Syndrome Inflammatory Bowel Disease Etiology and Pathogenesis Crohn Disease Ulcerative Colitis Infectious Enterocolitis Viral Infections Bacterial Infections Diverticular Disease Appendicitis Disorders of Intestinal Motility Diarrhea Constipation Acute Intestinal Obstruction Peritonitis Disorders of Intestinal Absorption Malabsorption Syndrome Celiac Disease Colorectal Neoplasms Adenomatous Polyps Colorectal Cancer

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