What is viral gastroenteritis?
Viral gastroenteritis is an inflammation of your stomach and intestines caused by one of any number of viruses. Also known as the stomach flu, viral gastroenteritis affects people throughout the world.

This highly contagious illness spreads through close contact with people who are infected or through contaminated food or water.

It can easily spread in close quarters, such as:

child care facilities
nursing homes
cruise ships
Different viruses can cause the illness, each with their own peak season. The most common viruses include norovirus and rotavirus.

There are steps you can take to lower your chances of contracting the viruses that cause viral gastroenteritis. These include frequent hand-washing and avoiding contaminated water and food products.

Most people make a full recovery in two or three days, with no lasting side effects.

What causes viral gastroenteritis?
Viral gastroenteritis is caused by a number of different viruses. People at higher risk are:

children under age 5
older adults, especially if they live in nursing homes
children and adults with compromised immune systems
It’s easy for this virus to spread in group situations. Some of the ways the virus is transmitted include:

improper hand-washing, especially by food handlers
water contaminated by sewage
consuming raw or undercooked shellfish from contaminated waters
Learn more about the individual viruses that can cause the condition.


Norovirus is highly contagious and can affect anyone at any age. It’s spread through contaminated food, water, and surfaces, or by people who have the virus. Norovirus is common in crowded spaces.

Symptoms include:

body aches
According to the Centers for Disease Control and Prevention (CDC)Trusted Source, most people with norovirus feel better within one to three days of experiencing symptoms.

Norovirus is the leading causeTrusted Source of gastroenteritis in the United States and worldwide. Most outbreaks in the United States occur between November and AprilTrusted Source.


Rotavirus commonly affects infants and young children. They can then spread the infection to other children and adults. It’s usually contracted and transmitted through the mouth.

Symptoms typically appear within two days of infection and include:

loss of appetite
watery diarrhea lasting anywhere from three to eight days
According to the CDC, this virus is most common between the months of December and JuneTrusted Source.

A rotavirus vaccine was approved for infants in 2006. Early vaccination is recommended to prevent severe rotavirus illnesses in infants and small children.


The adenovirus affects people of all ages. It can cause several conditions, including gastroenteritis.

Adenovirus is contracted through the air via sneezing and coughing, by touching contaminated objects, or by touching the hands of someone with the virus.

Symptoms associated with adenovirus include:

sore throat
pink eye
runny nose
Children in day care, especially those ages 6 months to 2 years, are more likely to get adenovirus.

Most children will feel better within a few days of experiencing adenovirus symptoms. However, symptoms such as pink eye may take longer to go away.


Astrovirus is another virus that commonly causes gastroenteritis in children. Symptoms associated with astrovirus include:

mild dehydration
stomach pain
The virus usually affects people in late winter and early spring. It’s passed through contact with a person who has the virus or an infected surface or food.

Symptoms usually appear within two to three days after initial exposure, and the virus will usually go away within two to three days.

What are the symptoms of viral gastroenteritis?
Symptoms of gastroenteritis usually begin one or two days after infection and include:

nausea and vomiting
headache, muscle aches, or joint aches
fever or chills
sweating or clammy skin
abdominal cramps and pain
loss of appetite
These symptoms can last anywhere from 1 to 10 days.

You should seek emergency medical treatment if:

diarrhea has lasted for three days or more without getting less frequent
blood is present in your diarrhea
you show or see signs of dehydration, such as dry lips or dizziness
In addition to the above symptoms, you should seek emergency attention for your child if they have the appearance of sunken eyes or if they aren’t making tears when they cry.

What conditions may resemble viral gastroenteritis?
Sometimes other factors can cause symptoms that closely resemble viral gastroenteritis. These causes include:

Food intolerance. Examples of common food intolerances include lactose, fructose, and artificial sweeteners.
Digestive disorders. These include inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis; irritable bowel syndrome; or celiac disease.
Certain medications. Antibiotics or antacids with magnesium can cause similar symptoms to the stomach flu.
If your symptoms don’t get better in two to three days, you should see your doctor.

What are the complications of viral gastroenteritis?
The main complication of viral gastroenteritis is dehydration, which can be quite severe in babies and young children. Other complications include:

nutritional imbalances
muscle weakness
Dehydration can be life-threatening. Call your doctor if you or your child have these symptoms:

diarrhea lasting more than a few days
blood in your stool
confusion or lethargy
feeling faint or dizzy
dry mouth
an inability to produce tears
no urine for more than eight hours or urine that is dark yellow or brown
sunken eyes
sunken fontanel on an infant’s head
The dehydration that can accompany viral gastroenteritis can lead to several complications of its own. These include:

brain swelling
hypovolemic shock, a condition that occurs when your body doesn’t have enough fluid or blood
kidney failure
To prevent complications, you should seek immediate medical attention if you or your child have symptoms of dehydration.

How is viral gastroenteritis diagnosed?
Most of the time, a medical history and physical exam is the basis for diagnosis, especially if there’s evidence that the virus is spreading through your community.

Your doctor may also order a stool sample to test for the type of virus or to find out if your illness is caused by a parasitic or bacterial infection.

How is viral gastroenteritis treated?
The main focus of treatment is to prevent dehydration by drinking plenty of fluids. In severe cases, hospitalization and intravenous fluids are necessary.

Over-the-counter oral rehydration solutions (OHS), such as Pedialyte, can be helpful in mild cases. They are made to be easy on your child’s stomach, and they contain a balanced mixture of water and salts to replenish essential fluids and electrolytes.

These solutions are available at local pharmacies and don’t require a prescription. However, you should follow instructions carefully.

Shop for oral rehydration solutions such as Pedialyte.

Shop for oral electrolyte products.

Antibiotics have no effect on viruses. Check with your physician before taking any over-the-counter medications.

What to eat and what to avoid

As you start to feel better and reintroduce foods into your diet, it’s usually best to opt for bland foods. These foods include:

These foods are easier to digest and less likely to cause further stomach upset. Until you’re feeling better, you may want to avoid certain items, such as:

high-fat foods
sugary foods
dairy products
Self-care steps

If you have viral gastroenteritis, there are some self-care steps you can take.

Drink extra fluids with and between meals. If you have difficulty, try drinking very small amounts of water or sucking on ice chips.
Avoid fruit juices as these don’t replace minerals and can actually increase diarrhea.
Children and adults can use sports drinks to replenish electrolytes. Younger children and infants should use products formulated for children, such as OHS.
Eat food in small amounts and let your stomach recover.
Get lots of rest. You may feel tired or weak.
Check with your doctor before taking medications or giving them to children. Never give aspirin to children or teenagers with a viral illness. This can cause Reye’s syndrome, a potentially life-threatening condition.