696
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
G
Disorders of
Gastrointestinal
Function
29
C h a p t e r
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
