Gastroenteritis is an inflammation of the digestive tract, particularly
the stomach, and large and small intestines. Viral and bacterial
gastroenteritis are intestinal infections associated with symptoms of
, abdominal cramps,
Gastroenteritis is an uncomfortable and inconvenient ailment, but is
rarely life-threatening in the United States and other developed nations.
Viral gastroenteritis is frequently referred to as the stomach or
intestinal flu, although the
virus is not associated with this illness.
Viral gastroenteritis is one of the most common acute (sudden-onset)
illnesses in the United States, with millions of cases reported annually.
Each year, an estimated 220,000 children younger than age five are
hospitalized with gastroenteritis symptoms. Of these children, 300 die as
a result of severe diarrhea and
. In developing nations, diarrheal illnesses are a major source of
Causes and symptoms
Gastroenteritis is caused by the ingestion of viruses, certain bacteria,
or parasites. Food that has spoiled may also cause illness. Young children
may develop signs and symptoms of gastroenteritis as a reaction to a new
Viral infection is the most common cause of gastroenteritis. Viral
gastroenteritis is highly contagious and can be spread through close
contact with an infected person. Exposure also can occur through the
fecal-oral route, such as by consuming foods or beverages contaminated by
fecal material related to poor sanitation or poor hygiene, or by touching
contaminated surfaces and then touching the mouth and ingesting the germs.
The four types of viruses that cause most viral gastroenteritis include
rotavirus, adenovirus, calicivirus, and astrovirus.
Typically, children ages three to 15 months are more vulnerable to
rotaviruses, the most significant cause of acute watery diarrhea.
Outbreaks of diarrhea caused by rotaviruses are common during the winter
and early spring months, especially in child care centers. Symptoms in
children last for three to eight days, and occur one to two days after
exposure to the virus. Worldwide, rotaviruses are estimated to cause
800,000 deaths annually in children under five years of age. 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.
Children under age two are more susceptible to adenovirus serotypes 40 and
41. Vomiting and diarrhea symptoms occur about one week after exposure to
Calciviruses cause infection in people of all ages. This family of viruses
includes the noroviruses (such as the Norwalk virus) and the sapoviruses
(such as the sapporo virus). Calciviruses are transmitted from
person-to-person contact, as well as through contaminated water or food.
These viruses are the most likely to produce vomiting as a major symptom.
Muscle aches also are common symptoms. The symptoms usually appear within
one to three days after exposure to the virus.
Astrovirus primarily infects infants, young children, and the elderly.
This virus is most active during the winter months. Symptoms of vomiting
and diarrhea appear within one to three days after exposure to the virus.
BACTERIAL AND PARASITIC INFECTIONS
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 worsen
underlying problems in sanitation and food safety.
In developed nations, including the United States, bacterial
gastroenteritis may result from contaminated water supplies, improperly
processed or preserved foods, or person-to-person contact in places such
as child-care centers. 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
Escherichia coli (E. coli)
, bacterial causes of food borne illnesses, have caused increased concern
in developed nations.
remain two diseases of great concern in developing countries, and
research to develop long-term vaccines against them is underway.
bacteria are dangerous because they attack the intestinal wall and cause
Parasitic infections that cause gastroenteritis are most commonly caused
, which is easily spread through contaminated water and human contact.
is another common parasitic organism that causes the symptoms of
Gastroenteritis symptoms include
nausea and vomiting
, watery diarrhea, and abdominal
and cramps. These symptoms are sometimes accompanied by bloating, low
, and overall tiredness or weakness. Gastroenteritis symptoms typically
last two to three days, but some viruses may last up to a week.
Infants, young children, the elderly, and anyone with an underlying
disease are more vulnerable to complications of gastroenteritis. 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 become prolonged. Untreated, severe dehydration can
be life threatening. Dehydration should be suspected if symptoms of a dry
mouth, increased or excessive thirst, or decreased urination are
If symptoms do not resolve within one week, an infection or disorder more
serious than gastroenteritis may be involved. Prompt medical attention is
required if the child has any of these symptoms:
If a child has the following symptoms, the parent should contact the
A usual bout of gastroenteritis should not require a visit to the doctor.
However, medical treatment is essential if symptoms worsen or if the child
has any symptoms of dehydration.
A physician makes the diagnosis of gastroenteritis based on the presence
of symptoms and after performing a medical examination. 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
rotavirus, disease-causing (pathogenic) bacteria, or parasites.
When symptoms continue even after treatment or to rule out the presence of
other illnesses with similar symptoms, the diagnostic evaluation may
include blood tests, a hydrogen breath test, or an x ray of the bowel,
called a barium enema. Endoscopic tests such as a colonoscopy or
sigmoidoscopy may be performed. An endoscopic test is an internal
examination of the colon using a flexible instrument (sigmoidoscope or
colonoscope) inserted through the anus. When symptoms persist, a
, performed by a registered dietitian, may be included in the
child's diagnostic evaluation.
Gastroenteritis is a self-limiting illness that will resolve by itself.
(such as Tylenol) or ibuprofen (such as Advil or Motrin) should be used
sparingly for relief of discomfort. Parents should ask the child's
doctor for specific guidelines. Should pathogenic bacteria or parasites be
identified in the patient's stool sample, medications such as
will be prescribed. Over-the-counter antidiarrheal medications such as
Imodium should not be given to the child unless advised by the
child's doctor, as these drugs may make it more difficult for the
child's body to eliminate the virus.
An adequate intake of liquids and oral rehydrating solutions may be enough
to treat mild dehydration. More severe dehydration requires medical
treatment with intravenous (IV) fluids and may require
. IV therapy can be followed with oral rehydration as the patient's
condition improves. Once normal hydration is achieved and symptoms have
cleared, the patient can resume a regular diet.
It is important for the child to stay hydrated and nourished during a bout
of gastroenteritis. Formula feeding and breastfeeding should continue as
normal. If dehydration is absent, drinking generous amounts of fluids,
such as water or juice, is adequate.
should be avoided since it increases urine output and can contribute to
or worsen dehydration. Dairy products, sugary beverages and foods, highly
seasoned foods, and fatty or fried foods should be avoided until symptoms
When diarrhea and vomiting symptoms have subsided, plain foods can be
given. The traditional BRAT diet—bananas, rice, applesauce, and
toast—is tolerated by the tender gastrointestinal system. Other
foods can be gradually reintroduced into the diet once the child is
Minimal to moderate dehydration can be treated by giving the child
generous amounts of fluids, including water, clear liquids, and oral
rehydrating solutions containing glucose and electrolytes. Oral
rehydrating solutions—including brands such as Pedialyte, Infalyte,
Ceralyte, and Oralyte—are available at most grocery and drug
stores. They are essential for replacing fluids,
, and salts lost from diarrhea or vomiting, and should be given when
diarrhea or vomiting first occur.
Small sips of water, clear liquids, or ice chips are usually tolerated
better than a large glass of liquid given all at once.
If the water supply is thought to be contaminated because of a recent
storm or other reason, the water should be boiled or bottled water should
The Centers for Disease Control and Prevention (CDC) recommends that
families with infants and young children keep a supply of oral rehydration
solution (two bottles or packages) at home at all times. However, it is
important to make sure that the product has not expired before giving it
to the child. Parents and caregivers should follow usage directions on the
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.
Alternative and complementary therapies include approaches that are
considered to be outside the mainstream of traditional health care.
Symptoms of uncomplicated gastroenteritis can be relieved with adjustments
in diet and homeopathy.
Probiotics, bacteria that are beneficial to a person's health, are
recommended during the recovery phase of gastroenteritis. Specifically,
live cultures of
are said to be effective in soothing the digestive tract and returning
the intestinal flora to normal.
is found in live-culture yogurt, as well as in capsule or powder form at
health food stores. The use of probiotics has some support in the medical
literature. Castor oil packs applied to the abdomen can reduce
inflammation and also lessen spasms or discomfort.
Before using any alternative remedy, it is important for the
parent/caregiver and child to learn about the therapy, its safety and
effectiveness, and potential side effects. Although some remedies are
beneficial, others may be harmful to certain patients. Dietary supplements
should not be used as a substitute for medical therapies prescribed by a
doctor. Parents should discuss these alternative treatments with the
child's doctor to determine the techniques and remedies that may be
beneficial for the child.
For most people, gastroenteritis is not a serious illness. It typically
resolves within two to three days and there are usually no long-term
effects. If dehydration occurs, recovery is extended by a few days.
Gastroenteritis is not an anatomical or structural defect, nor is it an
identifiable physical or chemical disorder.
—An x ray of the bowel using a liquid called barium to enhance
the image of the bowel. This test is also called a lower GI
—An examination of the lining of the colon performed with a
—Difficult bowel movements caused by the infrequent production of
—The act of having a bowel movement or the passage of feces
through the anus.
—An excessive loss of water from the body. It may follow
vomiting, prolonged diarrhea, or excessive sweating.
—A loose, watery stool.
—Salts and minerals that produce electrically charged particles
(ions) in body fluids. Common human electrolytes are sodium chloride,
potassium, calcium, and sodium bicarbonate. Electrolytes control the
fluid balance of the body and are important in muscle contraction,
energy generation, and almost all major biochemical reactions in the
—Visual examination of an organ or body cavity using an
endoscope, a thin, tubular instrument containing a camera and light
source. Many endoscopes also allow the retrieval of a small sample
(biopsy) of the area being examined, in order to more closely view the
tissue under a microscope.
—The solid waste, also called stool, that is left after food is
digested. Feces form in the intestines and pass out of the body through
—A physician who specializes in diseases of the digestive system.
—A simple sugar that serves as the body's main source of
Hydrogen breath test
—A test used to determine if a person is lactose intolerant or if
abnormal bacteria are present in the colon.
—An infectious disease caused by a virus that affects the
respiratory system, causing fever, congestion, muscle aches, and
Intravenous (IV) therapy
—Administration of fluids or medications through a vein, usually
in the hand or arm.
—A sugar found in milk and milk products.
—The bacterial population in the intestine.
—Bacteria that produce illness.
—Bacteria that are beneficial to a person's health, either
through protecting the body against pathogenic bacteria or assisting in
recovery from an illness.
—A procedure in which a thin, flexible, lighted instrument,
called a sigmoidoscope, is used to visually examine the lower part of
the large intestine. Colonoscopy examines the entire large intestine
using the same techniques.
Research is underway involving vaccines that will decrease the risk of
rotavirus infection, especially among infants and young children.
Parents should reinforce with the child that gastroenteritis is not a
serious condition and that symptoms usually subside in a few days. It is
most important to prevent dehydration by following the recommendations
listed previously. Parents should assure that the child gets adequate
rest; the child should be kept home from school or
until the symptoms have cleared. The child may be contagious before the
onset of diarrhea and a few days after the diarrhea has ended. To prevent
the spread of infection among family members, soiled clothing or bedding
should be washed in hot water immediately, hands must be washed
frequently, there should be no sharing of utensils or cups used by the
child, and toys and bathroom surfaces should be cleaned with a
DeWit, Matty A.S., et. al. "Risk Factors for Nororvirus,
Sappporo-like Virus, and Group A Rotavirus Gastroenteritis."
Emerging Infectious Diseases
9, no. 12 (December, 2003): 1563–70. Available online at:
American College of Gastroenterology (ACG).
P.O. Box 3099, Alexandria, VA 22302. (703) 820-7400. Web site:
American Gastroenterological Association.
4930 Del Ray Ave., Bethesda, MD 20814. (301) 654-2055. Patient
Information Resources. Web site:
Centers for Disease Control and Prevention.
1600 Clifton Rd., Atlanta, GA 30333. (800) 311-3435 or (404) 639-3534.
Web site: http://www.cdc.gov.
National Institute of Diabetes and Digestive and Kidney Diseases
2 Information Way, Bethesda, MD 20892-3570. (800) 891-5389. Web site:
"Gastroenteritis." September 24, 2003.
Available online at:
"Gastrointestinal Infections and Diarrhea."
. Nemours Foundation, February 2002. Available online at:
"Viral Gastroenteritis." [cited August 20, 2001].
Centers for Disease Control.
Available online at: