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Viral gastroenteritis is an inflammation and irritation of your intestines caused by one of a number of viruses, most commonly norovirus or rotavirus. This illness is also known as the stomach flu.

This highly contagious illness spreads through close contact with people who have the virus or through contaminated food or water.

It can easily spread in close quarters, such as:

  • childcare facilities
  • schools
  • nursing homes
  • cruise ships

This article will help you understand more about viral gastroenteritis including symptoms, causes, treatment, and prevention.

Symptoms of gastroenteritis usually begin shortly after infection. For example, symptoms caused by norovirus typically develop within 12 to 48 hours. Symptoms from adenoviruses may be delayed 3 to 10 days after contact.

Depending on which type of virus you’ve contracted, symptoms can last anywhere from 1 to 14 days. Symptoms often start suddenly over the course of 1 or 2 hours.

Symptoms can include:

Diarrhea caused by viral gastroenteritis isn’t usually bloody. Blood in your stool could be a sign of a more severe infection.

You should seek emergency medical treatment if:

  • diarrhea has lasted for 2 days or more without getting less frequent
  • your infant develops diarrhea
  • 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.

Viral gastroenteritis is caused by a number of different viruses. It’s easy for these viruses to spread in group situations. Some of the ways the virus is transmitted include:

  • eating contaminated food or drinking contaminated water
  • being in close contact with someone who has the virus
  • sharing utensils or other items with someone who has the virus
  • touching contaminated surfaces
  • not washing hands properly, especially food handlers

Viral gastroenteritis affects people of all ages all over the world. But some factors can increase the risk of contracting viral gastroenteritis. People who are at a higher risk include:

  • children under the age of 5
  • older adults, especially those who live in nursing homes or assisted living facilities
  • people with a compromised or weakened immune system
  • those who are often in group settings, such as schools, dormitories, day care, religious gatherings, and other indoor group settings

Other factors that may increase the risk of becoming ill with viral gastroenteritis include:

Several different types of viruses can cause viral gastroenteritis. The most common include:

  • norovirus
  • rotavirus
  • adenovirus
  • astrovirus

Let’s look at each of these viruses in more detail.

Norovirus

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

Norovirus is the leading cause of gastroenteritis in the United States and worldwide. Most outbreaks in the United States occur between November and April.

Symptoms include:

According to the Centers for Disease Control and Prevention (CDC), most people who become ill with norovirus start to feel better within 1 to 3 days of symptom onset.

Rotavirus

Rotavirus commonly affects infants and young children. Those who contract it can then pass the virus to other children and adults. It’s usually contracted and transmitted via the mouth.

Symptoms typically appear within 2 days of infection and include:

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

Adenovirus

The adenovirus affects people of all ages. It can cause several types of illness, including gastroenteritis. The adenovirus can also cause common cold-like symptoms, bronchitis, pneumonia, and pink eye (conjunctivitis).

Children in daycare, especially those under 2 years of age, are more likely to get adenovirus.

Adenovirus is passed 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:

Most children will feel better within a few days of experiencing adenovirus symptoms. However, symptoms such as pink eye may last longer than a few days.

Astrovirus

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

The virus most often affects people in late winter and early spring. It’s transmitted through contact with a person who has the virus or via an infected surface or food.

Symptoms usually appear within 2 to 3 days after initial exposure, and the virus will usually go away within 1 to 4 days.

The main complication of viral gastroenteritis is dehydration, which can be quite severe in babies and young children. Viral gastroenteritis accounts for over 200,000 childhood deaths worldwide per year.

Other complications of viral gastroenteritis include:

Dehydration can be life threatening. Call your doctor if you or your child have these symptoms:

Dehydration that accompanies viral gastroenteritis can lead to several complications of its own. These include:

To prevent complications, get immediate medical attention if you or your child have symptoms of dehydration.

Most of the time, your medical history and physical exam are 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.

The main focus of treatment is to prevent dehydration by drinking plenty of fluids. In severe cases, hospitalization and intravenous fluids may be necessary.

Over-the-counter oral rehydration solutions (OHS), such as Pedialyte, can be helpful in mild cases. These solutions are easy on your child’s stomach, and 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 the instructions carefully.

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

Shop online for oral rehydration solutions such as Pedialyte and oral electrolyte products.

Treating diarrhea and vomiting

Diarrhea can be treated in adults with over-the-counter medications such as loperamide (Imodium) or bismuth subsalicylate (Pepto-Bismol).

Your doctor may also prescribe probiotics to replace the healthy bacteria that’s lost during diarrhea or they may prescribe medications to treat severe vomiting.

What to eat and what to avoid

As you start to feel better and reintroduce foods into your diet, it’s best to opt for bland foods, such as:

  • rice
  • potatoes
  • toast
  • bananas
  • applesauce

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

In addition to rehydrating and resting, there are some natural and home remedies that may help you relieve the symptoms of viral gastroenteritis.

Heating pad or heat pack

If you have abdominal pain, try applying a low-temperature heating pad or a warm heat pack to your stomach. Cover the heating pad with a cloth and don’t leave it on for more than 15 minutes at a time.

The heat can help relax the muscles in your digestive tract and keep them from spasming.

Shop online for heating pads and heat packs.

Brown rice water

Some parents serve rice water to their children. This is the water that remains after boiling brown rice. It’s high in electrolytes and can help with rehydration.

To make rice water:

  1. Boil 1 cup of rice and 2 cups of water for about 10 minutes until the water becomes cloudy.
  2. Strain the rice and keep the water.
  3. Cool the rice water before serving.

Ginger

Products containing ginger, such as ginger ale or ginger tea, may help soothe an upset stomach.

A 2019 review of studies found that a divided daily dose of 1,500 milligrams of ginger taken in two parts throughout the day may help reduce nausea. More research needs to be done on ginger’s ability to treat other gastrointestinal symptoms.

Shop online for ginger ale and ginger tea.

Mint

Mint may also have anti-nausea properties similar to those of ginger. Sipping a soothing mint tea may help you feel better.

Studies have found that peppermint oil may help relax the muscles in your gut. It also has anti-microbial and anti-inflammatory properties.

Shop online for mint tea.

Yogurt or kefir

Although dairy products should be avoided when you have your most acute symptoms, eating unflavored yogurt with live active cultures or drinking kefir may help restore your body’s natural bacterial balance after illness.

Shop online for plain yogurt and kefir.

Viral gastroenteritis can spread easily. However, there are some steps you can take to lower your risk of contracting the virus or passing it to others.

Viral gastroenteritis is an inflammation and irritation of your intestines caused by one of several types of viruses.

Vomiting and diarrhea are among the most common symptoms. You can get viral gastroenteritis from other people or through contaminated foods, drinks, or surfaces.

Generally, viral gastroenteritis symptoms come on suddenly and pass quickly. If diarrhea lasts longer than 48 hours, be sure to follow up with your doctor.

It’s also a good idea to get medical attention if your infant or young child develops diarrhea because it can lead to serious complications due to dehydration.