Child Stomach Flu Symptoms and Treatments

Give Your Kids Plenty of Fluids to Prevent Dehydration

Mother taking son's temperature
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The term "stomach flu" can be confusing. It has nothing to do with the influenza virus or the regular flu that can cause a cough, runny nose, fever, and body aches. It usually refers to a virus, often a norovirus or rotavirus, and includes symptoms such as diarrhea and vomiting.

Since the stomach flu really has nothing to do with influenza, the flu, or the flu shot, it is probably better to call it by its proper name— gastroenteritis. Young children—particularly under 5 years old—are at a high risk and it's estimated that it is responsible for 1.5 million outpatient visits and 200,000 hospitalizations each year. 

Causes

Gastroenteritis can be caused by viruses, bacteria, or parasites, though viruses are the leading cause. These cases are called viral gastroenteritis, though you may also hear it called acute gastroenteritis. Acute means that the symptoms appear quickly.

Norovirus and rotavirus are the two types of viruses responsible for most cases of viral gastroenteritis. According to the Merck Manual, norovirus is most common in the United States and rotavirus the most common worldwide. In some cases, astrovirus or adenovirus may be responsible.

These viruses are spread from one infected person to another. Children are often exposed to them in school, daycare, and other public venues, including swimming pools. It is commonly spread through improper handwashing after using the bathroom or from caretakers who do not wash their hands after changing diapers or performing similar tasks. The virus can live on toys, books, or food and infect the next child. Sneezing and spitting can also spread the virus.

Bacterial gastroenteritis may be caused by E. coli, salmonella, and other bacterias from contaminated foods or beverages, including water. It can also be contracted by touching animals—primarily amphibians, birds, and reptiles—that contain the bacteria.

Contaminated water is a primary cause of gastroenteritis from parasites and chemical toxins, such as arsenic, cadmium, lead, and mercury. Some medications may have diarrhea as a side effect and this may develop into gastroenteritis as well.

Symptoms

Vomiting and diarrhea are the two primary symptoms of viral gastroenteritis. Other symptoms may include:

  • Nausea
  • Low-grade fever
  • Abdominal cramps
  • Headache
  • Poor appetite

These stomach flu symptoms can begin one to two days after being exposed (the incubation period) to someone else that is sick with a stomach flu virus. It can last for one to 10 days, depending on the virus that causes it. For instance, rotavirus can last for five to seven days while norovirus will typically only last for one to three days.

Less common symptoms of the stomach flu can include chills and muscle aches.

Children who have excessive diarrhea or vomiting or who are not able to drink enough fluids can also develop symptoms of dehydration, the primary concern with the stomach flu. Signs of mild dehydration to watch out for include:

  • A moist mouth and tongue
  • Normal to slightly decreased urine output
  • Less than 3 percent weight loss
  • Warm extremities

It is especially important to watch for signs of severe dehydration, including the child becoming lethargic, irritable, or listless. Infants are especially prone to serious dehydration and need to see a doctor immediately. Look for these signs in babies:

  • No tears when crying
  • A sunken soft spot on the head
  • Sunken eyes or cheeks
  • Dry mouth
  • Reduced urine (3 hours or more without a wet diaper)
  • Reduced energy

Treatments

As with many other viral infections, there is no specific "cure" for the stomach flu. And stomach viruses won't be affected one way or the other by a flu shot since it's not a true strain of influenza. There are, however, two vaccines available for preventing rotavirus that your pediatrician may recommend during an infant vaccination.

When a child gets the stomach flu, care is aimed more at preventing dehydration and includes routine treatments for vomiting and diarrhea, This includes giving fluids, of course, but it also means avoiding things that might make their vomiting or diarrhea worse.

Antidiarrheal medications are usually not recommended. Antibiotics are not usually an effective course of treatment, since most stomach ailments of this nature are caused by viruses and not bacteria.

Concentrate first on getting your child to drink a lot of fluids so they don't become dehydrated. Once they are keeping fluids down, you can advance them back to their regular diet.

For a short time, some parents like to limit their kids to what's known as the BRAT diet: Bananas, rice, applesauce, and toast. Since these starchy foods are constipating, they may help ease diarrhea. But the BRAT diet is very low in nutrients, and should not be used long-term.

In addition to restricting a child's diet, another common misconception when treating diarrhea is that Pedialyte or other electrolyte solutions will make diarrhea go away. Pedialyte isn't a cure for rotavirus and other causes of diarrhea though. Instead, it just helps prevent your child from getting dehydrated.

The only time that Pedialyte is recommended is when a child has a lot of vomiting. Even then, very small amounts are recommended: Between a teaspoon or tablespoon, every five or ten minutes until the child is keeping fluids down. You can then slowly advance how much he is drinking as he vomits less and eventually start him back on his regular diet as tolerated.

A Word From Verywell

In general, the stomach flu is an infection that simply needs to pass, and it typically does without complication. Dehydration is the biggest worry, so keep your kids hydrated and watch for the signs of dehydration. If you notice any of those, see your doctor right away. It's also a good idea to call their office for advice whenever your child has symptoms of the stomach flu, just to be on the safe side.

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Article Sources
  • Boyce TG. Overview of Gastroenteritis. Merck Manual: Professional Edition. 2017.
  • Churgay CA. Gastroenteritis in Children: Part I. Diagnosis. American Family Physician. 2012;85(11):1059–1062.
  • Cochran WJ. Gastroenteritis in Children. Merck Manual: Consumer Edition. 2017.
  • National Institute of Diabetes and Digestive and Kidney Diseases. Viral Gastroenteritis ("Stomach Flu"). National Institutes of Health. 2018.