Vomiting and Diarrhea in Children: Preventing Dehydration and Knowing When to Seek Care

What causes vomiting and diarrhea?

Most vomiting and diarrhea in children is caused by a virus.

Common causes include:

• Norovirus
• Rotavirus
• Adenovirus
• Other common gastrointestinal viruses

Norovirus is now one of the most common causes of acute vomiting and diarrhea in children and adults.

These infections can spread easily from person to person and through contaminated food, water, hands, and surfaces.

Less commonly, diarrhea or vomiting may be caused by:

• Bacterial infections such as Salmonella or Campylobacter
• Parasites
• Food reactions
• Medications
• Other medical conditions

Not every episode of vomiting is caused by a stomach infection.

Vomiting can occasionally be a sign of another problem, which is why the warning signs later in this guide are important.

What counts as diarrhea?

Children's stools can normally vary considerably, especially in babies.

Breastfed babies, for example, may normally have frequent loose stools.

Diarrhea is more concerning when there is a clear change from your child's usual pattern, especially a sudden increase in the number and looseness of stools.

Several watery or very loose stools in a day are more suggestive of diarrhea than one isolated loose stool.

The child's age, usual stool pattern, associated symptoms, and hydration all matter.

The main goal at home: prevent dehydration

Vomiting and diarrhea cause the body to lose both water and important salts.

Replacing those fluids is the most important part of treatment.

Use an oral rehydration solution

Products such as Pedialyte are designed specifically to replace both water and electrolytes.

For most children with mild to moderate dehydration, oral rehydration works very well and can often prevent the need for intravenous fluids.

Give small amounts frequently

When your child is vomiting, avoid offering a large drink all at once.

Instead, offer small amounts frequently.

For example:

• A teaspoon or tablespoon every few minutes
• Small sips from a cup
• Small amounts from an oral syringe for younger children

Small amounts are less likely to trigger another episode of vomiting.

If the fluid stays down, gradually increase the amount.

Replacing ongoing fluid losses

After each episode of vomiting or diarrhea, offer additional oral rehydration solution.

A practical guide is:

These are practical replacement amounts, not rigid requirements.

If your child is vomiting, give the fluid gradually rather than all at once.

Younger children may tolerate a few milliliters every few minutes better than several ounces at one time.

Keep breastfeeding and usual formula

Babies who are breastfed should usually continue breastfeeding throughout the illness.

Frequent breastfeeding can provide both fluid and nutrition.

Formula-fed babies can generally continue their usual formula.

There is usually no need to dilute formula or switch to a different type simply because the baby has diarrhea.

What should my child drink?

When dehydration is a concern, an oral rehydration solution is preferred because it contains the right balance of water, sugar, and electrolytes.

Full-strength:

• Juice
• Soda
• Sports drinks
• Other very sugary drinks

are not ideal rehydration fluids and may worsen diarrhea because of their high sugar content.

Plain water alone is also not appropriate as the main rehydration fluid for young infants.

For some older children with mild illness who refuse oral rehydration solution, half-strength apple juice or a half-strength sports drink may sometimes be a reasonable temporary option.

Oral rehydration solution remains preferred when a child is dehydrated or at significant risk of dehydration.

Getting back to eating

You do not need to “rest the stomach” by withholding food for long periods.

Once your child is drinking adequately and vomiting is improving, offer their usual age-appropriate foods.

Most children can return to a normal diet within a few hours.

Foods such as:

• Rice
• Pasta
• Bread
• Potatoes
• Yogurt
• Fruits
• Vegetables
• Lean meats
• Other familiar foods

are all reasonable depending on what your child normally eats and tolerates.

The old restrictive BRAT diet—bananas, rice, applesauce, and toast—is not necessary and does not provide enough nutrition to be used as a prolonged diet.

What about medicines?

Anti-nausea medicine

Anti-nausea medicines are not routinely needed for every child.

In some situations, a doctor may prescribe ondansetron to help a child stop vomiting long enough to drink successfully and avoid intravenous fluids.

Do not give prescription anti-nausea medicine unless it was specifically recommended for your child.

Anti-diarrhea medicine

Over-the-counter anti-diarrhea medicines are not routinely recommended for young children.

Do not give them unless your child's clinician specifically advises it.

Antibiotics

Antibiotics usually do not help because most childhood gastroenteritis is viral.

They are used only when a specific bacterial infection or another condition warrants treatment.

Probiotics

Probiotics are sometimes suggested during diarrhea, but the evidence for benefit varies depending on the product and the cause of diarrhea.

Ask your child's clinician if you are considering one.

How can I tell if my child is becoming dehydrated?

Watch for:

• Much less urine than usual
• Fewer wet diapers
• Going more than about 8 hours without urinating
• A very dry mouth or tongue
• No tears when crying
• Sunken-looking eyes
• A sunken soft spot in an infant
• Unusual weakness or sleepiness
• Becoming very difficult to wake
• Fast breathing
• Fast heartbeat

Mild dehydration is often manageable with oral fluids.

A child who is becoming increasingly sleepy, weak, or unable to drink needs medical evaluation.

When should I go to the emergency department?

Seek emergency medical care if your child has:

• Green or bile-colored vomit
• Blood in the vomit
• Severe or worsening abdominal pain with a swollen or very tender abdomen
• Extreme sleepiness, confusion, or inability to wake normally
• Severe difficulty breathing
• A seizure or other concerning neurologic symptoms
• Signs of severe dehydration together with inability to drink
• A very ill appearance or rapid worsening

For a possible life-threatening emergency, call 911.

When should I call the pediatrician or consider urgent care?

Contact your child's pediatrician or seek same-day evaluation if:

• Your child cannot keep fluids down despite frequent small sips
• You are concerned about dehydration
• There is blood in the stool
• Vomiting continues for more than about 24 hours
• Diarrhea is severe or continues for about a week or longer
• Your child has persistent or significant abdominal pain
• Your child has a high or persistent fever
• A baby younger than 3 months has a fever
• A young infant has repeated vomiting or frequent watery diarrhea
• Your child is drinking poorly or urinating much less than usual
• Your child seems substantially more ill than expected with a routine stomach infection
• You simply feel that something is wrong

Trust your instincts.

You know your child best.

Preventing the spread

Stomach viruses spread very easily.

A few steps help reduce transmission:

• Wash hands thoroughly with soap and water after diaper changes, after using the bathroom, and before preparing or eating food.
• Clean and disinfect surfaces contaminated by vomit or stool.
• Wash contaminated clothing and bedding promptly.
• Avoid sharing cups, utensils, and food when someone is sick.
• Keep sick children home from school or daycare until they are well enough to return and meet the facility's return requirements.

A note about norovirus

For norovirus, soap and water are particularly important.

Alcohol-based hand sanitizer does not work as reliably against norovirus and should not replace good handwashing.

Rotavirus vaccination

Rotavirus vaccination has dramatically reduced severe rotavirus gastroenteritis in babies and young children.

The vaccine is given by mouth during infancy and helps protect against one of the historically important causes of severe childhood diarrhea and dehydration.

The bottom line

Most vomiting and diarrhea in children improves on its own.

The most important treatment is replacing fluids and preventing dehydration.

Use oral rehydration solution when dehydration is a concern, offer small amounts frequently after vomiting, continue breastfeeding or usual formula, and return to normal age-appropriate foods as your child improves.

Pay attention to urine output, alertness, and your child's ability to drink.

Seek emergency care for green vomit, blood in vomit, severe abdominal symptoms, severe dehydration, or a child who appears critically ill.

When you are unsure, contacting your child's pediatrician is always reasonable.