atitis nearly always goes away with abstinence
from alcohol though any CIRRHOSIS(replacement of
liver tissue with SCARtissue) that has already devel-
oped is permanent. Nonalcoholic steatohepatitis
associated with diabetes generally improves with
tighter management of the diabetes, and with obe-
sity when weight loss occurs. Microvesicular
steatohepatitis may require extensive support,
including intravenous fluids and nutrients, during
its acute phase. For many people recovery is com-
plete and without residual damage to the liver.
See also DIET AND HEALTH; LIVER DISEASE OF ALCO-
HOLISM.
steatorrhea Excessive excretion of fat in the
stool. Steatorrheic stools are often foamy and foul-
smelling, and tend to break apart and float in the
toilet bowl. Steatorrhea is a symptom of numer-
ous gastrointestinal disorders including MALAB-
SORPTION, CELIAC DISEASE, GALLBLADDER DISEASE,
PANCREATITIS, and LIVER disease. Treating the
causative condition ends the steatorrhea.
See also CONSTIPATION; CYSTIC FIBROSIS; DIARRHEA.
stomach The pouchlike organ that receives and
digests food. The stomach can stretch up to six
times its resting size to accommodate influxes of
food and drink up to about the combined quantity
of a gallon. Three layers of MUSCLEwrap around
the deeply pitted gastric mucosa (mucous mem-
brane lining of the stomach). The fibers of each
muscle layer run in different directions: the layer
innermost to the mucosa is oblique (diagonal), the
middle layer of muscle is horizontal (encircles the
stomach), and the outermost layer runs length-
wise. This arrangement allows the stomach to flex
and contract in every direction to mix and break
apart food particles.
CONDITIONS THAT CAN AFFECT THE STOMACHBEZOAR Crohn’s disease
CYCLIC VOMITING SYNDROME DYSPEPSIA
GASTRITIS GASTROESOPHAGEAL REFLUX
GASTROPARESIS DISORDER(GERD)
HIATAL HERNIA PEPTIC ULCER DISEASE
STOMACH CANCER ZOLLINGER-ELLISON SYNDROME
The stomach produces gastric acid, which is pri-
marily hydrochloric acid, and several DIGESTIVE
ENZYMES. Though the stomach digests carbohy-
drates and some proteins, its primary role is to
prepare food for the SMALL INTESTINEwhere the
bulk of digestion takes place.
For further discussion of the stomach within
the context of gastrointestinal structure and func-
tion, please see the overview section “The Gas-
trointestinal System.”
See also COLON; DIET AND HEALTH; DIGESTIVE HOR-
MONES; ESOPHAGUS; GASTRECTOMY; HELICOBACTER
PYLORI; H 2 ANTAGONIST (BLOCKER) MEDICATIONS;
INFLAMMATORY BOWEL DISEASE(IBD); NAUSEA; NUTRI-
TIONAL DEFICIENCY; PROTON PUMP INHIBITOR(PPI) MED-
ICATION; VOMITING.stomach cancer Malignant growths that occur in
the STOMACH. Stomach CANCERis seventh among
deaths from cancer in the United States. About 90
percent of stomach cancers are adenocarcinomas,
malignant growths that originate in the glandular
cells that carpet the gastric mucosa. These are the
cells that produce the stomach’s acid and mucus, as
well as DIGESTIVE ENZYMES. Though stomach cancer
readily metastasizes (spreads) to other tissues and
organs, the stomach is seldom the site of secondary
cancers that originate elsewhere in the body.
Though the causes of stomach cancer remain a
mystery, researchers do know certain factors alter
the DNAof cells in the stomach in ways that result
in the uncontrolled growth that characterizes can-
cer. These factors cause chronic irritation to the
stomach tissues. They include- INFECTIONwith HELICOBACTER PYLORI, believed to
cause about 85 percent of PEPTIC ULCER DISEASE - a diet high in red meats, well-done barbecued
meats, and smoked meats and fish that contain
nitrates or nitrites (which convert to carcino-
genic substances during the digestive action of
gastric juices) as preservatives - the combination of cigarette smoking and
excessive ALCOHOLconsumption - untreated or poorly controlled GASTROE-
SOPHAGEAL REFLUX DISORDER(GERD) or Crohn’s
disease
Symptoms and Diagnostic Path
Symptoms of early stomach cancer are often
vague and nonspecific, such as DYSPEPSIA, NAUSEA90 The Gastrointestinal System