GastroIntestinal / Gastroenterology Infectious Diseases / Bacteria / Viruses Pediatrics / Children's Health

Stomach flu: In adults and infants, how long does it last?

The name that individuals typically use to characterize viral gastroenteritis is stomach flu. Many variables determine how long it lasts, but within days it usually resolves.

In the gastrointestinal ( GI ) tract, the stomach flu causes inflammation, irritation, and swelling. It is relatively short-lived in most situations, and does not need medication.

Viral gastroenteritis may be responsible for many viral infections, including:

  • Norovirus: This virus is the most common cause in adults.
  • Rotavirus: This type of infection tends to affect infants aged 3–15 months.
  • Adenovirus: Adenoviruses affect children under 2 years of age.

None of the viruses that cause stomach flu are linked to influenza, despite its name. The GI tract is infected by multiple viruses, causing symptoms including nausea , vomiting and diarrhea.

The age of a person and the form of viral infection will play a role in how long the flu lasts in the stomach.

We include more detail on the duration of stomach flu in this article, including how long it stays contagious. We also offer some tips on recovery.

How long does stomach flu last?

A lady having stomach flu

Stomach flu does not usually last for a long period of time. Different viruses, however, can cause individuals to feel ill for different periods of time.

Norovirus

Norovirus is the most common cause of stomach flu, according to the Centers for Disease Control and Prevention ( CDC), causing 19-21 million cases per year in the United States.

In general, norovirus symptoms last for around 1-2 days.

The virus spreads very quickly and can live for several days or even weeks on surfaces. Because of this, in shared enclosed spaces such as day care centers and nursing homes, it can spread especially quickly.

The CDC states that from the day a person begins experiencing symptoms to a few days after the symptoms ease, the virus becomes transmissible.

Therefore, once they realize that they have symptoms, it is necessary for a person with norovirus to avoid close contact with others for several days.

Avoiding catching it is the best defense against norovirus.

The CDC suggests that individuals take the following precautions to stop or prevent the virus from being caught:

  • washing the hands thoroughly after using the bathroom or handling diapers and before eating
  • cleaning and disinfecting surfaces that come into contact with vomit or diarrhea
  • washing fruits and vegetables thoroughly and cooking seafood to a safe temperature
  • washing laundry thoroughly
  • refraining from preparing food or caring for other people when sick

Rotavirus

According to the CDC, the people most at risk of getting rotavirus include:

  • children aged 3 months to 3 years
  • older adults
  • adults who work with children
  • people with a compromised immune system

A rotavirus vaccination is available. Usually, doctors send babies two to three times the dose of the vaccine between the ages of 2 and 6 months.

Fever, stomach pain , vomiting, and severe, watery diarrhea can cause rotavirus. Around 2 days after exposure to the virus, a person typically develops symptoms.

It can take 3–8 days for the symptoms to clear. From touching infected stools, objects, or food, a person can get rotavirus.

Adenovirus

The American Thoracic Society notes that many different viruses actually contain adenovirus.

They also note that they can develop symptoms within 2 days to 2 weeks after a person has had adenovirus exposure. Adenovirus can cause upper and lower respiratory symptoms as well as neurological and eye problems, in addition to GI symptoms.

It takes about 5–7 days for adults and children who are otherwise in good health to recover from the viral infection.

However, it can spread to others even though the virus is no longer causing symptoms. The Adenovirus can also live on hard surfaces for up to 30 days.

Stomach flu in children

In young children, rotavirus and adenovirus are also common causes of stomach flu. It can last about 3-8 days for rotavirus, and it can last about 5-7 days for adenovirus.

Sick young children are most at risk of developing dehydration.

In babies, parents and caregivers should watch for signs of dehydration. They include:

  • urine that is darker in color
  • thirst
  • dizziness
  • less frequent urination
  • dry skin

How long is the virus contagious?

Viruses responsible for the stomach flu stayed contagious even after the infection passes.

Therefore, after the symptoms pass, they are still transmissible from a person for several days.

For several days to weeks, these viruses may live on surfaces as well.

When someone in a household or other shared residence comes down with the stomach flu, individuals should wash all surfaces to remove the virus.

Recovery tips

To help improve their recovery, people should take a few easy measures at home.

Tips for children

To help accelerate recovery in infants or children with stomach flu, parents and caregivers should try the following:

  • continuing formula feeding or breastfeeding the infant as long as they can keep it down
  • starting solid foods slowly with easy-to-digest foods
  • avoiding giving too much water to older children
  • avoiding giving water to a baby with the stomach flu
  • asking a pediatrician about drinks to aid rehydration
  • providing light fluids in the form of diluted juices, broths, and ice chips

Tips for adults

People can help themselves recover by:

  • avoiding large meals
  • resting as much as possible
  • drinking sports drinks and plenty of water
  • eat softer, easy-to-digest foods, such as noodles, rice, and oatmeal

When to see a doctor
The virus will run its course within a couple of days for most children and adults and will not require any special medical care.

An individual should, however, look out for symptoms that may suggest a more serious problem. Signs of dehydration should be observed by parents and guardians of babies and young children.

Also, a person should call their doctor if:

  • the child or infant has blood in their stool
  • The stool is tar-like in form.
  • symptoms do not improve within a few days
  • the child or infant develops signs of severe dehydration

Summary

In children or adults, the stomach flu does not last for long.

Depending on the virus that triggers it, it normally clears up within 2–8 days.

There are no formal remedies, but the effects can be relieved by rest, fluids, and easy-to – digest foods.

The virus could still be infectious for several days after a person’s symptoms go away.

By avoiding direct contact with others who have the disease, people may reduce their chance of getting sick. If anyone has the stomach flu in their home, they should thoroughly clean all surfaces and wash any sheets, bedding, and other products the person uses.