Version July 2025
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What is gastroenteritis? —
"Gastroenteritis" means inflammation of the stomach and intestines (figure 1). It can be caused by a viral or bacterial infection. One of the most common causes of gastroenteritis is norovirus. But other viruses and bacteria can cause it, too.
People can get gastroenteritis if they:
●Touch an infected person or a surface with the virus or bacteria on it, and then don't wash their hands. Babies and toddlers can get sick if they put their hands or other objects in their mouths.
●Eat foods or drink liquids with the virus in them. If people with an infection don't wash their hands, they can spread the germ to foods or liquids they touch. When a person gets sick from something they ate, it is often called "food poisoning."
What are the symptoms of gastroenteritis? —
The main symptoms are diarrhea, vomiting, or both. These symptoms usually start suddenly, and can be severe.
Gastroenteritis caused by an infection can also cause:
●Fever
●Headache or muscle aches
●Belly pain or cramping
●Loss of appetite
If your child has a lot of diarrhea and vomiting, their body can lose too much water. This is known as "dehydration." Dehydration can make a person feel thirsty, tired, dizzy, or even confused. It can also make their urine look dark yellow.
Severe dehydration can be life-threatening. Babies and young children are more likely to get severe dehydration.
Will my child need tests? —
Not usually. Their doctor or nurse should be able to tell if they have gastroenteritis by learning about their symptoms and doing an exam. But the doctor or nurse might do tests to check for dehydration or find out what type of virus or bacteria is causing the infection.
Tests can include:
●Blood tests
●Urine tests
●Tests on a sample of bowel movement
Is there anything I can do to help my child feel better? —
Yes. Children and babies with gastroenteritis need to replace fluids that are lost through vomiting and diarrhea:
●Have your child drink fluids when they are able. It might help to have them take small sips every 15 to 30 minutes. Try to have them drink more as they start to feel better.
●When a child or baby has a lot of vomiting or diarrhea, their body loses both water and salt. Having them drink fluids that contain some salt can help replace what their body has lost. Your child's doctor or nurse can help you decide which fluid is best:
•Babies who breastfeed should continue to breastfeed.
•Your child's doctor or nurse might recommend "oral rehydration solutions," such as Pedialyte. You can buy this in a store or pharmacy. If your child is vomiting, try to give them a few teaspoons of fluid every few minutes.
•Avoid giving your child drinks with a lot of sugar, like juice or soda.
•If your child or baby drinks a lot of plain water, make sure that they are also eating (or breastfeeding). This will help their body keep the right salt and water balance.
●Try to have your child eat when they are able. If they can keep food down, it's best to eat lean meats, fruits, vegetables, and whole-grain breads and cereals. Avoid giving foods with a lot of fat or sugar, which can make symptoms worse.
Do not give children medicines to stop diarrhea, such as loperamide (brand names: Imodium, Diamode) or diphenoxylate and atropine (brand name: Lomotil).
If your child has diabetes, you might need to check their blood sugar more often until they feel better. Ask your child's doctor or nurse about this.
How is gastroenteritis treated? —
Most children and babies do not need any treatment, because their symptoms will get better on their own. But children and babies with severe dehydration might need treatment in the hospital. This involves getting fluids through a thin tube that goes into a vein, called an "IV."
If gastroenteritis was caused by a viral infection, antibiotics will not help. That's because antibiotics only work on bacteria, not viruses. For gastroenteritis caused by bacteria, antibiotics are sometimes used, but not always. This depends on what type of infection the child has and how severe it is.
Can gastroenteritis be prevented? —
Sometimes. To lower the chance of your child getting or spreading infections, you can:
●Wash your hands with soap and water often (figure 2). This is especially important after you use the bathroom or change your child's diaper, and before you eat. Hand sanitizer does not work against some viruses, like norovirus.
●Make sure that your child washes their hands with soap and water after they use the bathroom and before they eat. For younger children, you might need to help them wash their hands.
●Avoid changing your child's diaper near where you prepare food.
●Make sure that your baby gets the rotavirus vaccine. Vaccines can prevent certain serious or deadly infections. Rotavirus commonly causes viral gastroenteritis in children.
When should I call the doctor? —
Call the doctor or nurse if your child:
●Has any symptoms of dehydration, like feeling very tired, thirsty, dizzy, or confused
●Has diarrhea or vomiting that lasts longer than a few days
●Vomits up blood, has bloody diarrhea, or has severe belly pain
●Hasn't been able to drink anything for a few hours (for children)
●Hasn't needed to urinate for 6 to 8 hours (during the day), or hasn't had a wet diaper for 4 to 6 hours
Patient education: Dehydration in children (The Basics)
Patient education: Nausea and vomiting in babies and children (The Basics)
Patient education: Diarrhea in children (The Basics)
Patient education: Food poisoning (The Basics)
Patient education: Vaccines for babies and children age 0 to 6 years (The Basics)
Patient education: Rotavirus infection (The Basics)
Patient education: Salmonella infection (The Basics)
Patient education: E. coli diarrhea (The Basics)
Patient education: Acute diarrhea in adults (Beyond the Basics)
Patient education: Acute diarrhea in children (Beyond the Basics)
Patient education: Nausea and vomiting in infants and children (Beyond the Basics)
Patient education: Foodborne illness (food poisoning) (Beyond the Basics)
