Viral gastroenteritis (stomach flu)
Viral gastroenteritis is present when a virus causes an infection of the stomach and intestine. The infection can lead to diarrhea and vomiting. It is sometimes called the "stomach flu."
Rotavirus infection - gastroenteritis; Norwalk virus; Gastroenteritis - viral; Stomach flu; Diarrhea - viral; Loose stools - viral; Upset stomach - viral
Gastroenteritis can affect one person or a group of people who all ate the same food or drank the same water. The germs may get into your system in many ways:
Many types of viruses can cause gastroenteritis. The most common viruses are:
People with the highest risk for a severe infection include young children, older adults, and people who have a suppressed immune system.
Symptoms most often appear within 4 to 48 hours after contact with the virus. Common symptoms include:
Other symptoms may include:
Exams and Tests
The health care provider will look for signs of dehydration, including:
Tests of stool samples may be used to identify the virus that is causing the sickness. Most of the time, this test is not needed. A stool culture may be done to find out if the problem is being caused by bacteria.
The goal of treatment is to make sure the body has enough water and fluids. Fluids and electrolytes (salt and minerals) that are lost through diarrhea or vomiting must be replaced by drinking extra fluids. Even if you are able to eat, you should still drink extra fluids between meals.
Try eating small amounts of food frequently. Foods to try include:
If you have diarrhea and are unable to drink or keep down fluids because of nausea or vomiting, you may need fluids through a vein (IV). Infants and young children are more likely to need IV fluids.
Parents should closely monitor the number of wet diapers an infant or young child has. Fewer wet diapers is a sign that the infant needs more fluids.
People taking water pills (diuretics) who develop diarrhea may be told by their provider to stop taking them until symptoms improve. However, DO NOT stop taking any prescription medicine without first talking to your provider.
Antibiotics do not work for viruses.
You can buy medicines at the drugstore that can help stop or slow diarrhea.
For most people, the illness goes away in a few days without treatment.
Severe dehydration can occur in infants and young children.
When to Contact a Medical Professional
Call your provider if diarrhea lasts for more than several days or if dehydration occurs. You should also contact your provider if you or your child has these symptoms:
Contact your provider right away if you or your child also have respiratory symptoms, fever or possible exposure to COVID-19.
Most viruses and bacteria are passed from person to person by unwashed hands. The best way to prevent stomach flu is to handle food properly and wash your hands thoroughly after using the toilet.
Be sure to observe home isolation and even self-quarantine if COVID-19 is suspected.
A vaccine to prevent rotavirus infection is recommended for infants starting at age 2 months.
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DuPont HL, Okhuysen PC. Approach to the patient with suspected enteric infection. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 267.
Kotloff KL. Acute gastroenteritis in children. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 366.
Melia JMP, Sears CL. Infectious enteritis and proctocolitis. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 110.
Review Date: 4/30/2020
Reviewed By: Bradley J. Winston, MD, board certified in gastroenterology and hepatology, Washington, DC. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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