an embolism. Wet gangrene develops
when dry gangrene or a wound becomes
infected by bacteria. The gangrene
spreads and gives off an unpleasant
smell. There may be redness, swelling,
and oozing pus around the blackened
area. A virulent type called gas gan-
grene is caused by a bacterium that
destroys muscles and produces a foul-
smelling gas.
Treatment of dry gangrene consists of
attempting to improve the circulation
to the affected area before the tissues
die. Antibiotic drugscan prevent wet
gangrene from setting in. Amputationof
the affected part and the surrounding
tissue is necessary.
Ganser’s syndromeA rare factitious
disorderin which a person seeks, con-
sciously or unconsciously, to mislead
others about his or her mental state and
may simulate symptoms of psychosis.
Gardnerella vaginalisA bacteriumthat
is oftenfound in the vaginal discharge
of women with nonspecific vaginitis.
gargleA liquid preparation to wash and
freshen the mouth and throat. Some
gargles contain antisepticsor local anaes-
theticsto relieve sore throats.
gas-and-airA mixture of nitrous oxide
and oxygenthat is used mainly used for
temporary emergency pain relief.
gastrectomyRemoval of the stomach
(total gastrectomy) or, more commonly,
part of the stomach (partial gastrec-
tomy). Total gastrectomy is used to
treat some stomach cancers. Partial gas-
trectomy used to be a treatment for
peptic ulcers but has largely been
replaced by drug treatment.
Possible postoperative complications
are fullness and discomfort after meals;
regurgitation of bile, which may lead to
gastritis, oesophagitis, and vomiting of
bile; diarrhoea; and dumping syndrome.
Other complications include malab-
sorption, which may lead to anaemiaor
osteoporosis. After total gastrectomy,
patients cannot absorb vitamin B 12 and
are given it in the form of injections for
the rest of their lives.
gastric erosionA break in the surface
layer of the membrane lining the stom-
ach. A break deeper than this layer is
called a gastric ulcer (see peptic ulcer).
Gastric erosions occur in some cases of
gastritis. Many erosions result from
ingestion of alcohol, irontablets, or
aspirin. The physical stress of serious
illness, such as kidney failure, or of
burnsmay bring on an erosion. Often
there are no symptoms, but erosions
may bleed, causing vomiting of bloodor
blood in the faeces. Persistent loss of
blood may lead to anaemia. Gastric
erosions are diagnosed by gastroscopy.
They usually heal in a few days when
they are treated with antacid drugsand
ulcer-healing drugs.
gastric ulcerSee peptic ulcer.
gastrinA hormoneproduced by cells in
the stomachlining. Gastrin causes the
stomach to produce more acid and
helps to propel food through the diges-
tive tract. (See also gastrointestinal
hormones.)
gastritisInflammationof the stomach
lining. This may be acuteor chronic.
Acute gastritis may be caused by irrita-
tion of the stomach lining by drugs,
usually aspirinor other NSAIDs; by alco-
hol; or by infection with a HELICOBACTER
bacterium. Severe physical stress, such
as burnsor liver failure, can bring on
gastritis. Chronic gastritis may be due
to prolonged irritation of the stomach
by alcohol, tobacco-smoking, or bile; by
an autoimmune disorderthat damages
the stomach lining (see anaemia, mega-
loblastic); or by degeneration of the
lining with age.
Symptoms include discomfort in the
upper abdomen, nausea, and vomiting.
In acute gastritis, the faeces may be
blackened by blood lost from the stom-
ach; in chronic gastritis, slow blood loss
may lead to anaemia (see anaemia,
iron-deficiency). Diagnosis is made with
gastroscopy, during which a biopsyof
the stomach lining may be performed.
Ulcer-healing drugsmay be given.
gastroenteritisInflammation of the
stomachand intestines, usually causing
sudden upsets that last for 2 or 3 days.
Dysentery, typhoid fever, cholera, food
poisoning, and travellers’ diarrhoeaare
all forms of gastroenteritis. The illness
may be caused by any of a variety of
bacteria, bacterial toxins, viruses, and
other organisms in food or water.GANSER’S SYNDROME GASTROENTERITIS
G