Stomach viruses typically last a few days but can sometimes last a week or more. In some cases, they may cause longer lasting effects on a person’s health.

Stomach viruses cause symptoms that typically include watery diarrhea, vomiting, and abdominal pain.

People may also refer to viral gastroenteritis, or inflammation of the stomach and intestines due to viral infection, as “stomach flu.” Two examples of stomach viruses are rotavirus and norovirus. Both are highly contagious, so a person should avoid going to school or work for the duration of the infection.

In most people, the symptoms of a stomach virus will come and go within a few days. However, some people may experience symptoms for a longer period. Some individuals may also develop long lasting complications.

This article reviews how long stomach virus symptoms typically last, potential long-term effects, possible treatment options, tips for recovery, and when to see a doctor.

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According to the United Kingdom’s National Health Service, the most common cause of gastroenteritis — inflammation in the intestines and stomach — in children is the rotavirus. However, adults can also contract this virus.

The rotavirus typically incubates for 2 days. A person will often have symptoms for 3–8 days after the incubation period. A vaccine is available to help prevent infants from contracting the rotavirus.

The adenovirus and astrovirus also often affect children. The adenovirus typically incubates for 3–10 days, and symptoms last 1–2 weeks. The astrovirus usually incubates for 4–5 days and causes symptoms for 1–4 days.

The norovirus is the most common cause of stomach flu. The incubation period is 12–48 hours, and symptoms typically last 1–3 days.

For most people, the stomach flu is a self-limiting infection. This means that, with or without treatment, a person should typically recover within about a week.

However, some research suggests that the stomach flu can have long lasting effects on a person’s health in some cases.

One area of concern is the gut microbiota, which consists of a large variety of bacteria and other microorganisms that help break down foods and may play a role in several aspects of a person’s health. According to an older 2012 study, acute infections may affect the gut microbiota and lead to long term health complications.

In a 2017 study, researchers looked at how acute viral gastroenteritis affects the gut microbiota in children. They found that intestinal microbiota diversity was lower in people with severe acute viral gastroenteritis than in those with milder acute viral gastroenteritis and those without gastroenteritis.

The researchers suggested that this may happen due to an imbalance or disruption of the species in the microbiota after the infection.

Another possible complication of gastroenteritis is postinfection irritable bowel syndrome (IBS). Research suggests that 4–36% of people recovering from gastroenteritis develop postinfection IBS.

The condition causes chronic abdominal pain along with diarrhea, constipation, or both. Its development may relate to changes in the gut microbiota.

In cases of viral gastroenteritis, treatment typically focuses on preventing dehydration.

To do this, a person should replace and retain fluids and electrolytes by:

  • drinking plenty of fluids that contain electrolytes, such as:
  • eating saltines
  • drinking rehydration solutions, if the person with a stomach virus is a child or an older adult or has a weakened immune system

Adults may find that taking over-the-counter diarrhea medication may help as long as they do not experience bloody diarrhea or fever. Options include loperamide and bismuth subsalicylate. In some cases, a doctor may prescribe medication for severe vomiting.

After having the stomach flu, a person does not typically need to follow any special diet. Often, an adult or child can return to eating what they would usually eat once their appetite returns, even if they are still experiencing diarrhea.

A person should limit contact with other people for the first few days after contracting the virus, as they can still transmit it to others during this time. Some evidence suggests that people may be able to transmit norovirus for 2 weeks or longer after symptoms subside.

Learn more about how to kill and prevent spreading stomach viruses.

Most cases of stomach flu are self-limiting and will go away within about a week without any medical treatment.

However, people should drink plenty of fluids and look for symptoms of dehydration. If a person experiences severe dehydration, they may need to go to a hospital for treatment.

A person should also talk with a doctor if they develop any of the following symptoms:

If complications occur or symptoms last a long time, a person should consider consulting a healthcare professional for diagnosis and treatment.

Long lasting stomach viruses may occur in rare cases, possibly due to changes in the gut microbiota. However, most people should recover within about a week.

If complications occur, a person should consult a doctor to determine the underlying cause and receive appropriate treatment.

Otherwise, most stomach viruses clear up without treatment, and a person can return to their typical diet and lifestyle afterward.