704
U N I T 8
Gastrointestinal and Hepatobiliary Function
an artery or vein. It occurs in up to 20% of persons
with peptic ulcer.
7
Evidence of bleeding may consist of
hematemesis or melena. Bleeding may be sudden, severe,
and without warning, or it may be insidious, producing
only occult blood in the stool. Up to 20% of persons
with bleeding ulcers have no antecedent symptoms of
pain; this is particularly true in persons using NSAIDs.
Acute hemorrhage is evidenced by the sudden onset of
weakness; dizziness; thirst; cold, moist skin; the desire
to defecate; and the passage of loose, tarry, or even red
stools and coffee-ground emesis. Signs of circulatory
shock develop depending on the amount of blood lost.
Perforation occurs when an ulcer erodes through all
the layers of the stomach or duodenum wall. Perforation
develops in approximately 5% of persons with peptic
ulcers, usually from ulcers on the anterior wall of the
stomach or duodenum.
7
With perforation, gastrointesti-
nal contents enter the peritoneum and cause peritonitis.
Radiation of the pain into the back, severe night dis-
tress, and inadequate pain relief from eating foods or
taking antacids in persons with a long history of peptic
ulcer may signify perforation. Penetration is a process
similar to perforation, but with penetration the ulcer
crater erodes into adjacent organs, including the small
bowel, pancreas, liver, or biliary tree.
20
Typically, it has
a subtle presentation marked by a gradual increase in
severity and frequency of pain.
Gastric outlet obstruction is caused by edema, spasm,
or contraction of scar tissue and interference with the free
passage of gastric contents through the pylorus or adja-
cent areas. The presentation of an obstruction is typically
insidious, with symptoms of early satiety, feeling of epi-
gastric fullness and heaviness after meals, gastroesopha-
geal reflux, weight loss, and abdominal pain. With severe
obstruction, there is vomiting of undigested food.
Diagnosis and Treatment.
Diagnostic procedures for
peptic ulcer include history taking, laboratory tests,
radiologic imaging, and endoscopic examination. The
history should include careful attention to aspirin and
NSAID use. Peptic ulcer should be differentiated from
other causes of epigastric pain. Laboratory findings of
hypochromic anemia and occult blood in the stools
indicate bleeding. Endoscopy (i.e., gastroscopy and
duodenoscopy) can be used to visualize the ulcer area
and obtain biopsy specimens to test for
H. pylori
and
exclude malignant disease. X-ray studies with a contrast
medium such as barium are used to detect the presence
of an ulcer crater and to exclude gastric carcinoma.
The treatment of peptic ulcer has changed dramati-
cally over the past several decades and now aims to
eradicate the cause and promote a permanent cure for
the disease. Pharmacologic treatment focuses on eradi-
cating
H. pylori,
relieving ulcer symptoms, and heal-
ing the ulcer crater. Aspirin and NSAID use should be
avoided when possible. With current therapies aimed at
neutralization of gastric acid, inhibition of gastric acid
(H
2
antagonists and proton pump inhibitors), and pro-
motion of mucosal protection, most ulcers heal within
a matter of weeks. When surgery is needed, it usually is
performed using minimally invasive methods.
Zollinger-Ellison Syndrome
Zollinger-Ellison syndrome is a rare condition caused
by gastrin-secreting tumors (gastrinomas) that are most
commonly found in the small intestine or pancreas.
7
In
persons with this disorder, gastric acid secretion reaches
such levels that ulceration becomes inevitable. The
increased gastric secretions cause symptoms related to
peptic ulcer. Diarrhea may result from hypersecretion
of acid or from the activation of intestinal lipase and
impaired fat digestion that occurs with a decrease in
intestinal pH. Most gastrinomas are solitary or multi-
focal nodules that are potentially resectable. Over two
thirds of gastrinomas are malignant and one third have
metastasized at the time of diagnosis.
8
Stress Ulcers
A stress ulcer, sometimes called a
Curling ulcer,
refers
to gastrointestinal ulcerations that develop in relation
to major physiologic stress.
7,22,23
Persons at high risk for
development of stress ulcers include those with large–
surface-area burns, trauma, sepsis, acute respiratory
distress syndrome, severe liver failure, and major surgi-
cal procedures. These lesions occur most often in the
fundus of the stomach and proximal duodenum and are
thought to result from ischemia, tissue acidosis, and bile
salts entering the stomach in critically ill persons with
decreased gastrointestinal tract motility. Another form
of stress ulcer, called
Cushing ulcer,
consists of gastric,
duodenal, and esophageal ulcers arising in persons with
intracranial injury, operations, or tumors. They are
thought to be caused by hypersecretion of gastric acid
resulting from stimulation of vagal nuclei by increased
intracranial pressure.
Persons admitted to hospital intensive care units
are at particular risk for development of stress ulcers.
They usually manifest with painless upper gastrointes-
tinal tract bleeding. H
2
-receptor antagonists and proton
pump inhibitors are often used in the prevention and
treatment of stress ulcers.
Cancer of the Stomach
Although the incidence of cancer of the stomach has
declined over the past 50 years in the United States, it
continues to remain a leading cause of cancer deaths
worldwide.
6
It is more common in lower socioeconomic
groups and exhibits a male-to-female ratio of about 2:1.
Among the factors that increase the risk of gastric
cancer are genetic predisposition, carcinogenic factors in
the diet (e.g.,
N
-nitroso compounds and benzo[
α
]pyrene
found in smoked and preserved foods), autoimmune
gastritis, and gastric adenomas or polyps. The incidence
of stomach cancer in the United States has decreased
fourfold since 1930, presumably because of improved
storage of food with decreased consumption of smoked
and preserved foods.
6,7
Chronic infection with
H. pylori
appears to serve as a co-factor in some types of gastric
carcinomas. However, the vast majority of people with
H. pylori
infection do not develop gastric cancer, and
not all
H. pylori
infections increase the risk of gastric
