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What is vomiting?

Vomiting (throwing up) happens when very strong stomach contractions force a large part of the stomach contents back up the swallowing tube (esophagus) and out through the mouth or nose.

Vomiting is not the same as regurgitation. Regurgitation is the effortless spitting up of a small amount of food or liquid. Food goes up the esophagus and into the mouth. Regurgitation is very common in babies. It is not harmful. 

Vomiting can become serious if your child loses too much fluid and becomes dehydrated.

Causes of vomiting

Most often vomiting is caused by a viral infection known as gastroenteritis (stomach virus). The infection irritates the stomach and digestive system. Children with vomiting from gastroenteritis may also have diarrhea.

Other causes of vomiting include headaches or head injury, u​rinary tract infections​​, blocks in the intestinal tract, severe coughing, food allergies and food poisoning​. Medications or other substances such as alcohol can also irritate the stomach and cause vomiting.

If your child has severe vomiting or vomiting that does not go away, visit a health care professional.

How long will the vomiting last?

A viral gastroenteritis infection usually begins with vomiting and sometimes fever. The vomiting often lasts only 1 or 2 days, but may last longer.

A child will often have diarrhea at the same time or after the vomiting. The vomiting and diarrhea do not usually last longer than 1 week.

Taking care of your child at home

Give your child clear fluids. Your child will need to replace the water and salt they have lost from vomiting. The best fluid for your child is an oral rehydration solution since it replaces both the water and the electrolytes (salts) that they lost in their vomit or diarrhea (see below). Children who have had severe, prolonged diarrhea may have problems digesting milk and they may develop temporary lactose intolerance. However, if your child is vomiting, or if the diarrhea is not frequent and severe, then you can try giving your baby or child milk. In some cases, babies really want to drink their milk and this is the best way to help them stay hydrated.

Breast milk for breastfed babies

Breastfed babies with gastroenteritis should continue to drink breast milk. They can drink breast milk either from the breast or by taking expressed breast milk from a cup or bottle. If your baby vomits after feeding or is vomiting very often, keep breastfeeding. Feed your baby smaller amounts more often.

If you are breastfeeding and your baby is not drinking as much as usual, you may need to pump your milk to keep up your own milk supply and prevent discomfort.

If your breastfeeding baby is still thirsty after drinking breast milk, or if she keeps vomiting, you may offer oral rehydration solution. Offer oral rehydration as described below. Continue to either breastfeed or pump your breast milk.

If your baby normally takes formula, then you can continue to offer formula. If the baby refuses, you can try to offer one to two ounces of oral rehydration solution every 30 minutes. If your baby is getting better, then you can try to switch back to formula. 

If your baby is urinating (peeing) less often and you are not sure if you are making enough milk, offer your baby oral rehydration solution in between feedings. Do not give tea or plain water to babies who may be dehydrated.

See a doctor if you think that your baby is becoming dehydrated.

Oral rehydration solutions

If your child seems dehydrated (dry mouth, less active or peeing less often) give your child oral rehydration solution. This solution will give your child the water, sugar and salt that they need.

Examples of oral rehydration solutions are Pedialyte, Enfalyte or Pediatric Electrolyte. Generic brands are available and equally effective. You can buy oral rehydration solutions in most drug stores or grocery stores. Home-made solutions are not recommended, because having too much or too little salt can cause serious problems. 

Use a teaspoon, syringe or medicine dropper to give the fluid to your child. You can also use a bottle or cup.

Give your child a small amount of solution (5 mL or 1 teaspoon to start) every 2 to 3 minutes. If your child accepts and drinks the solution, gradually increase the amount. Increase the amount you give up to at most 1 ounce (30 mL) every 5 minutes. Do not give more than 1 ounce at a time. Encourage your child to drink slowly. Drinking quickly can cause vomiting. 

If your child is still vomiting, continue giving the oral rehydration solution 1 teaspoon (5 mL) at a time. If your child is still vomiting it does not mean that the oral rehydration solution is not working. The sugar, salt and liquid in the solution are still being absorbed.

Alternatives to regular oral rehydration solution

Some children may not like the salty taste of oral rehydration solution.

If your child does not want to take the oral rehydration solution, try serving the solution cold. Frozen oral rehydration solution (freezie) and popsicles are available. You can also try to change the brand or flavour of the oral rehydration solution.

If your child is still refusing, try the following:

  • Mix juice with the oral rehydration solution. Use 1 part juice to 2 parts oral rehydration solution.
  • Give your child an electrolyte sports drink like Gatorade or Powerade. You can buy these at the grocery store. These drinks are not the same as oral rehydration solutions, but they have more electrolytes than plain juice or soda pop.

Avoid sugary drinks

Many juices contain a lot of sugar, which may make diarrhea worse. If your child is having a lot of diarrhea, do not give juice or other sugary drinks. If your child is vomiting but does not have diarrhea, then you can give them juice.

Offer food

Your child should try to eat a normal diet even when they have gastroenteritis. Good nutrition is important to help your child feel better. Unless vomiting is very frequent, offer your child a food that they are familiar with. Many children prefer simple foods when they have been vomiting. It is important to be flexible and give your child something that they want to eat. Give foods like crackers, cereals, bread, rice, soup, fruits, vegetables and meat. Avoid giving your child very sugary foods if they have diarrhea.


If your child has a fever and feels uncomfortable, give acetaminophen (Tylenol, Tempra or other brands) or ibuprofen​ (Advil, Motrin or other brands). 

Contact your doctor if your child takes prescription medications and is having a hard time taking them during this illness.

Medications available over the counter (such as Gravol or other brands) are not always helpful. Sometimes they can cause sleepiness which makes it hard to give oral rehydration. In some cases of persistent vomiting, your doctor may prescribe an anti-vomiting medication such as ondansetron. Ondanestron​ is given as a single dose.

How to keep the rest of your family healthy

Make to sure to wash your hands and your child’s hands well. This is very important after using the toilet or putting a diaper on your child. This will help stop the illness from spreading in your family.

When to see a doctor

Go to the nearest Emergency Department or call 911 if:

  • your child has a head injury or may have been exposed to something poisonous
  • your child seems very dehydrated (no urine in 8 hours, very dry mouth, no tears, low energy or sunken eyes)
  • your child’s vomit is green, bloody, or dark brown (coffee colour)
  • your child has severe or worsening tummy pain
  • your child has trouble breathing
  • your child has a very bad headache or sore neck
  • your child’s skin is cold or not its usual colour
  • your child is very tired or difficult to wake up
  • your child appears to be very sick

Make an appointment with your child's doctor if:

  • you think your child may be starting to get dehydrated
  • the vomiting lasts longer than 24 hours if your child is under 2 years old  
  • the vomiting lasts longer than 48 hours if your child is older than 2 years old
  • your child's fever lasts more than 3 days
  • vomiting happens more than once a month or happens mostly at night or early morning
  • you have other concerns or questions

Key points

  • Vomiting is often caused by irritation of the stomach and digestive system from a viral infection known as gastroenteritis (stomach virus) although there are many other causes.
  • Vomiting usually lasts only 1 or 2 days, but may last longer.
  • Breastfed babies with gastroenteritis should continue to drink breast milk.
  • Give your child oral rehydration solution and other clear fluids. Avoid giving your child sugary drinks.   
  • Wash your hands and your child’s hands well.
  • Talk to your doctor if your child seems very dehydrated.

Elly Berger, BA, MD, FRCPC, FAAP, MHPE