Gastroenteritis is a catchall
term for infection or irritation of the digestive tract, particularly the stomach
and intestine. It is frequently referred to as the stomach or intestinal
flu, although the influenza virus is not associated with this illness.
Major symptoms include nausea and vomiting, diarrhea, and abdominal cramps.
These symptoms are sometimes also be accompanied by fever and overall
weakness. Gastroenteritis typically lasts about three days. Adults usually
recover without problem, but children, the elderly, and anyone with an
underlying disease are more vulnerable to complications such as dehydration.
Gastroenteritis is an
uncomfortable and inconvenient disease but it is rarely life threatening in
developed nations. However, an estimated 220,000 children younger than age
five are hospitalized with gastroenteritis symptoms in the United States
annually. Of these children, 300 die as a result of severe diarrhea and
dehydration. In developing nations, diarrheal illnesses are a major source
of mortality. In 1990, approximately three million deaths occurred
worldwide as a result of diarrheal illness.
The most common cause of
gastroenteritis is viral infection. Viruses such as rotavirus, adenovirus,
astrovirus, and calicivirus and small round-structured viruses (SRSVs) are
found all over the world. Exposure typically occurs through the fecal-oral
route, such as by consuming foods contaminated by fecal material related to
poor sanitation. However, the infective dose can be very low (approximately
100 virus particles), so other routes of transmission are quite probable.
Typically, children are more
vulnerable to rotaviruses, the most significant cause of acute watery
diarrhea. Annually, worldwide, rotaviruses are estimated to cause 800,000
deaths in children below age five. For this reason, much research has gone
into developing a vaccine to protect children from this virus. Adults can
be infected with rotaviruses, but these infections typically have minimal
or no symptoms.
These viruses are the most
likely to produce vomiting as a major symptom. Bacterial gastroenteritis is
frequently a result of poor sanitation, the lack of safe drinking water, or
contaminated food--conditions common in developing nations. Natural or
man-made disasters can make underlying problems in sanitation and food
safety worse. In developed nations, the modern food production system
potentially exposes millions of people to disease-causing bacteria through
its intensive production and distribution methods. Common types of
bacterial gastroenteritis can be linked to Salmonella and Campylobacter
bacteria; however, other bacteria are creating increased concern in
Causes & symptoms
Gastroenteritis arises from
ingestion of viruses, certain bacteria, or parasites. Food that has spoiled
may also cause illness. Certain medications and excessive alcohol can
irritate the digestive tract to the point of inducing gastroenteritis.
Regardless of the cause, the symptoms of gastroenteritis include diarrhea,
nausea and vomiting, and abdominal pain and cramps. Sufferers may also
experience bloating, low fever, and overall tiredness. Typically, the
symptoms last only two to three days, but some viruses may last up to a
A usual bout of
gastroenteritis shouldn't require a visit to the doctor. However, medical
treatment is essential if symptoms worsen or if there are complications.
Infants, young children, the elderly, and persons with underlying disease
require special attention in this regard.
The greatest danger presented
by gastroenteritis is dehydration. The loss of fluids through diarrhea and
vomiting can upset the body's electrolyte balance, leading to potentially
life-threatening problems such as heart beat abnormalities (arrhythmia).
The risk of dehydration increases as symptoms are prolonged. Dehydration
should be suspected if a dry mouth, increased or excessive thirst, or
scanty urination is experienced.
If symptoms do not resolve
within a week, an infection or disorder more serious than gastroenteritis
may be involved. Symptoms of great concern include a high fever (102° F
[38.9°C] or above), blood or mucus in the diarrhea, blood in the vomit, and
severe abdominal pain or swelling. These symptoms require prompt medical
The symptoms of
gastroenteritis are usually enough to identify the illness. Unless there is
an outbreak affecting several people or complications are encountered in a
particular case, identifying the specific cause of the illness is not a
priority. However, if identification of the infectious agent is required, a
stool sample will be collected and analyzed for the presence of viruses,
disease-causing (pathogenic) bacteria, or parasites.
Gastroenteritis is a
self-limiting illness which will resolve by itself. However, for comfort
and convenience, a person may use over-the-counter medications such as
Pepto Bismol to relieve the symptoms. These medications work by altering
the ability of the intestine to move or secrete spontaneously, absorbing
toxins and water, or altering intestinal microflora, that are the bacteria
present in the intestines. Some over-the-counter medicines use more than
one element to treat symptoms.
medications are ineffective and medical treatment is sought, a doctor may
prescribe a more powerful anti-diarrheal drug, such as motofen or lomotil.
Should pathogenic bacteria or parasites be identified in the patient's
stool sample, medications such as antibiotics will be prescribed.
It is important to stay
hydrated and nourished during a bout of gastroenteritis. If dehydration is
absent, the drinking of generous amounts of nonalcoholic fluids, such as
water or juice, is adequate. Caffeine, since it increases urine output,
should be avoided. The traditional BRAT diet--bananas, rice, applesauce,
and toast--is tolerated by the tender gastrointestinal system, but it is
not particularly nutritious. Many, but not all, medical researchers
recommend a diet that includes complex carbohydrates (e.g., rice, wheat,
potatoes, bread, and cereal), lean meats, yogurt, fruit, and vegetables. Milk
and other dairy products shouldn't create problems if they are part of the
normal diet. Fatty foods or foods with a lot of sugar should be avoided.
These recommendations are based on clinical experience and controlled
trials, but are not universally accepted.
Minimal to moderate
dehydration is treated with oral rehydrating solutions that contain glucose
and electrolytes. These solutions are commercially available under names
such as Naturalyte, Pedialyte, Infalyte, and Rehydralyte. Oral rehydrating solutions
are formulated based on physiological properties. Fluids that are not based
on these properties--such as cola, apple juice, broth, and sports
beverages--are not recommended to treat dehydration. If vomiting interferes
with oral rehydration, small frequent fluid intake may be better tolerated.
Should oral rehydration fail or severe dehydration occur, medical treatment
in the form of intravenous (IV) therapy is required. IV therapy can be
followed with oral rehydration as the patient's condition improves. Once
normal hydration is achieved, the patient can return to a regular diet.
There are few steps that can
be taken to avoid gastroenteritis. Ensuring that food is well-cooked and
unspoiled can prevent bacterial gastroenteritis, but may not be effective
against viral gastroenteritis.