What Is Diarrhea?

Diarrhea is frequent soft or loose bowel movements (poop). Most kids have diarrhea from time to time. It usually doesn't last long and often gets better on its own.

What Causes Diarrhea?

Diarrhea is usually caused by an infection in the intestines. The germs that cause the infection are:

  • viruses (most common)
  • bacteria
  • parasites

Viruses

Viral gastroenteritis (often called the "stomach flu") is a common illness in children. It causes diarrhea and, often, nausea and vomiting. The symptoms usually last a few days, but kids (especially babies) who can't take enough liquids may become dehydrated.

Rotavirus affects babies and young kids and can bring on watery diarrhea. Outbreaks are more common in the winter and early spring months, especially in childcare centers. The rotavirus vaccine can protect children from this illness.

Enteroviruses, like coxsackievirus, also can cause diarrhea in kids, especially during the summer months.

Bacteria

Many different types of bacteria can cause diarrhea, including E. coli, Salmonella, Campylobacter, and Shigella. These bacteria are often responsible for cases of "food poisoning," which can cause diarrhea and vomiting within a few hours after someone is infected.

Parasites

Parasitic infections that can cause diarrhea in children include giardiasis and cryptosporidiosis.

What Else Can Cause Diarrhea?

Kids can sometimes get diarrhea from:

What Are the Signs & Symptoms of Diarrhea?

Kids often get crampy belly pain first, followed by diarrhea that can last 3–5 days. Other symptoms may include:

  • fever
  • loss of appetite
  • nausea (an uncomfortable feeling before vomiting)
  • vomiting
  • weight loss
  • dehydration

How Do Doctors Find the Cause of Diarrhea?

Doctors will:

  • ask about what the child ate most recently, when symptoms began, and how often the diarrhea is happening
  • ask specific questions about the diarrhea: Is it watery? Is there blood in the poop? 
  • do an exam
  • sometimes, take a stool (poop) sample to send to a lab for analysis. This helps them find out which germ is causing the illness.

How Is Diarrhea Treated?

Viral diarrhea goes away on its own. Most kids with bacterial diarrhea need treatment with an antibiotic. Parasites always need treatment with anti-parasitic medicines.

Kids who aren't vomiting or becoming dehydrated can continue eating and drinking or breastfeeding as usual. Continuing a regular diet may even shorten the diarrhea episode. You may want to serve smaller portions of food until the diarrhea ends.

Don't give your child an over-the-counter anti-diarrhea medicine unless your doctor tells you to do so.

What if My Child Is Dehydrated?

For kids who show signs of mild dehydration, doctors recommend giving oral rehydration solutions (ORS). These are available in most grocery stores and drugstores without a prescription and replace body fluids as needed. Your doctor will tell you what kind to give, how much, and for how long.

Kids should not be rehydrated with water alone because it doesn't contain the right mix of sodium, potassium, and other important minerals and nutrients.

In some cases, kids with severe diarrhea may need to get IV fluids (given into a vein) at the hospital for a few hours to help treat the dehydration.

How Can Diarrhea Be Prevented?

It's almost impossible to prevent kids from ever getting diarrhea. But there are some ways to make it less likely:

  • Make sure kids wash their hands well and often, especially after using the toilet and before eating. Hand washing is the best way to prevent diarrheal infections that pass from person to person. Dirty hands carry germs into the body when kids bite their nails, suck their thumbs, eat with their fingers, or put any part of their hands into their mouths.
  • Keep bathroom surfaces like sinks and toilets clean.
  • Wash fruits and vegetables well before eating.
  • Clean kitchen counters and cooking utensils well after they've been in contact with raw meat, especially poultry.
  • Refrigerate meats as soon as possible after bringing them home from the store. Cook them until they're no longer pink. Refrigerate all leftovers as soon as possible.
  • Never drink from streams, springs, or lakes unless local health authorities have checked that the water is safe for drinking.
  • Avoid washing pet cages or bowls in the same sink that you use to prepare food. And try to keep pet feeding areas separate from family eating areas.

When Should I Call the Doctor?

Call your doctor if your child has diarrhea and is younger than 6 months old. Also call if your child has:

  • diarrhea many times a day or it lasts for more than 3 days
  • repeated vomiting and can't or won't drink fluids
  • severe belly pain
  • diarrhea that has blood in it

Call the doctor right away if your child seems dehydrated. Signs include:

  • a dry or sticky mouth
  • few or no tears when crying
  • eyes that look sunken
  • in a baby, the soft spot (fontanelle) on top of the head looks sunken
  • peeing less or fewer wet diapers
  • drowsiness or dizziness
Back to Articles

Related Articles

First Aid: Diarrhea

Diarrhea is common and usually not a sign of something serious. Find out what to do if your child has diarrhea.

Read More

Food Poisoning

Sometimes, germs can get into food and cause food poisoning. Find out what to do if your child gets food poisoning - and how to prevent it.

Read More

Dehydration

Sometimes kids lose fluids and salts through fever, diarrhea, vomiting, or sweating. Here are some tips on preventing or treating dehydration.

Read More

Rotavirus

Rotavirus infection affects most kids and is one of the most common causes of diarrhea. A vaccine to prevent it is now recommended for all kids.

Read More

First Aid: Vomiting

Vomiting can be caused by many things, most commonly gastroenteritis (the "stomach flu"). Here's what to do when your child throws up.

Read More

Hand Washing: Why It's So Important

Washing your hands well and often is the best way to keep from getting sick. Here's how to teach this all-important habit to your kids.

Read More

Campylobacter Infections

These bacterial infections can cause diarrhea, cramping, abdominal pain, and fever. Good hand-washing and food safety habits can help prevent them.

Read More

Shigella Infections (Shigellosis)

Shigella are bacteria that can infect the digestive tract and cause a wide range of symptoms, from diarrhea, cramping, vomiting, and nausea, to more serious complications and illnesses.

Read More

Produce Precautions

Kids need daily servings of fruits and vegetables. Here's how to make sure the produce you buy and prepare is safe.

Read More

Giardiasis

Giardiasis, one of the chief causes of diarrhea in the United States, is an intestinal illness caused by a microscopic parasite.

Read More

Stool Tests

Your child's doctor may order a stool collection test to check for blood, bacteria, ova, or parasites. Find out how this test is performed and when you can expect the results.

Read More

Word! Diarrhea

If you've ever had a bad time in the bathroom, then you know what this is.

Read More

Stomachaches

Ugh. Bellyaches. Find out what causes tummy trouble in this article for kids.

Read More

Why Do I Need to Wash My Hands?

Washing your hands is the best way to stop germs from spreading. Learn all about the best way to wash your hands in this article for kids.

Read More

Lactose Intolerance

If you have lactose intolerance, you're not alone. Millions of Americans have the condition. Check out these tips on dealing with lactose intolerance.

Read More

Lactose Intolerance

Kids with lactose intolerance have trouble digesting a type of sugar found in milk and other dairy foods. But by making smart choices, they can eat delicious foods without feeling sick.

Read More

Irritable Bowel Syndrome (IBS)

Irritable bowel syndrome (IBS) is a common intestinal problem that can cause cramps, gas, bloating, diarrhea, and constipation. Certain foods can trigger these problems. So can anxiety, stress, and infections.

Read More

Irritable Bowel Syndrome

Having irritable bowel syndrome can make a kid feel awful. The good news is that kids can take steps to feel better.

Read More

Irritable Bowel Syndrome

Some teens get stomachaches and diarrhea often. Read about irritable bowel syndrome (IBS), a common intestinal disorder that affects the colon.

Read More

Food Poisoning

The germs that get into food and cause food poisoning are tiny, but can have a powerful effect on the body. Find out what to do if you get food poisoning - and how to prevent it.

Read More

Food Poisoning

Did you ever eat something that made you feel ooky? It might have been food poisoning.

Read More

Diarrhea

Nearly everybody gets diarrhea every once in a while, and it's usually caused by gastrointestinal infections. It's nothing to be embarrassed about. Read this article to learn more.

Read More

Vomiting

Most vomiting is caused by gastroenteritis, and usually isn't serious. These home-care tips can help prevent dehydration.

Read More

Does My Child Need an Antibiotic? (Video)

Antibiotics are powerful medicines that can help kids feel better -- but only when they have certain illnesses. Find out if an antibiotic is right for your child.

Read More

Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.