Vomiting in children

What is vomiting?

Vomiting is a very common symptom experienced by children. It’s one of the most common reasons parents take their child to the doctor.

Vomiting can be caused by many different factors, but viral gastroenteritis (‘gastro’) is the most common cause of sudden vomiting in children. Vomiting from viral gastroenteritis usually clears up in a couple of days, but the diarrhoea usually goes on longer.

Babies often bring up small amounts of food after feeding — it’s known as posseting or reflux. It happens without any effort, in contrast to vomiting — which involves forceful contractions of the stomach to bring up the contents of the stomach.

Babies and children are especially at risk of dehydration when they are vomiting. They may not be able to take in enough fluids to make up for those lost when vomiting.

What symptoms can occur when children vomit?

Vomiting in children often happens with other symptoms, such as diarrhoea. Tell your doctor about any symptoms that your child may experience along with vomiting — it can help with diagnosis. Some other symptoms that can occur together with vomiting in children are:

Children can projectile vomit. Projectile vomiting is when they vomit out of their mouth so forcefully that it can travel over a metre. A child who projectile vomits should be taken straight to a hospital’s emergency department.

When should I take a child to the doctor?

If a child is vomiting and has any of the following conditions, you should take them to a hospital’s emergency department straightaway:

  • swollen or tender abdomen
  • stiff neck — with or without photophobia (pain when looking at bright lights)
  • high fever
  • blood in the vomit or in the stool (poo)
  • green-coloured vomit
  • vomiting early in the morning
  • projectile vomiting (where the vomit is ejected some distance)
  • bulging fontanelle in a baby
  • vomiting that isn’t stopping
  • they can’t keep fluids down
  • signs of dehydration, such as fewer wet nappies, darker coloured urine, or dry lips and mouth

Babies younger than 6 months should always be taken to the doctor if they have gastroenteritis.

What causes vomiting in children?

Some of the causes of vomiting in children are generally harmless, but some causes are potentially life threatening. Some are short term problems and others cause ongoing or recurrent vomiting.

Causes of vomiting in children include the following conditions:


Gastroenteritis (known as ‘gastro’ or a stomach bug) — is caused by an infection in the digestive system. Usually this infection is viral, but sometimes it’s bacterial. These infections are easily spread between people, especially children. Gastroenteritis causes vomiting, diarrhoea, fever and abdominal pain.

Children and small babies are more susceptible to becoming dehydrated from gastroenteritis and babies under 6 months should be seen by a doctor if they have gastroenteritis.

Rotavirus is one common cause of severe gastroenteritis in babies, but vaccination against it is available as part of the National Immunisation Program. Older children are more likely to have gastroenteritis caused by norovirus — known as ‘the winter vomiting bug’.

Food poisoning

Food poisoning is caused by germs growing in food that has been poorly prepared or stored. The symptoms are the same as those caused by gastroenteritis, but usually more severe. Again, babies and small children are more at risk of dehydration than older children and care should be taken to ensure they stay hydrated (see below).


Poisoning is most common in young children, who often learn about things by putting them in their mouths. Many household items are poisonous if swallowed. Symptoms of poisoning include nausea and vomiting, drowsiness, fits (seizures) or breathing difficulties.

If you think a child has swallowed a poisonous substance or someone has taken an overdose, contact the Poisons Information Centre by phoning 13 11 26 for advice (24 hours).

Do NOT attempt to make the child vomit, unless instructed by a medical professional.

Urinary tract infections

Vomiting can be a sign of a urinary tract infection (UTI) in children. They occur commonly in young children. The symptoms of UTIs in children are often vague but can include fever, tiredness, being irritable, pain when weeing, fewer wees than normal, and smelly urine.


Appendicitis is a medical emergency. If you think your child may have appendicitis, you should take them immediately to a doctor or hospital. A burst appendix can lead to a life-threatening infection.

Appendicitis causes pain around the belly button (navel) which then moves to the lower right side of the abdomen and becomes sharper. A child with appendicitis may complain of worsening tummy pain, lose their appetite, vomit, feel uncomfortable when sitting upright or standing up, and experience pain when moving. They may try to keep very still.


This happens when a part of the bowel slides into another adjoining part of the bowel, like a telescope. It is a serious condition, often causing a blockage (bowel obstruction) and preventing the normal flow of food or fluids. This can be fatal if not treated. Children with intussusception may have intermittent severe pain causing crying and distress. They may have bleeding from the bottom, vomiting, or be lethargic or listless — either all the time or in waves. In between the episodes, the child may seem relatively well.

Bowel obstruction

This is an emergency that needs immediate surgery. It happens more commonly in newborn babies. The baby may vomit, and have a swollen abdomen. The vomit may be stained green from bile. Bowel obstruction in older children may result from intussusception.

Pyloric stenosis

A narrowing of the valve between the stomach and the small intestine prevents food from entering the small intestine. This blockage affects very young babies, mainly those between 2 and 6 weeks’ old. It causes vomiting (which may be projectile) soon after feeding, and weight loss or not putting weight on. The baby will still be hungry after feeding. The vomiting is ongoing and becomes more forceful. If a baby has vomiting that doesn’t stop, you should see the doctor immediately.

Raised intracranial pressure

Raised pressure in the skull is a medical emergency and can cause headache and vomiting on waking up or that wakes the child from sleep. It may cause projectile vomiting. It can be caused by a head injury, tumour or meningitis.


Meningitis is an infection and swelling of the membrane that covers the brain and spinal cord, usually from a bacterial or viral infection. It is rare, but serious, and can quickly be fatal.

Meningitis can cause symptoms such as vomiting, fever, headache, a stiff neck and avoidance of bright lights (photophobia). There may be a skin rash that consists of small red or purple spots that don’t turn white when you press on them. Babies may be irritable and have a high-pitched cry. They may arch their back or hold their head back. The baby’s fontanelle (the soft spot on the top of the head) may be swollen and bulge.

If a baby or child has symptoms of meningitis, you should call triple zero (000) for an ambulance or go straight to emergency.

Diabetic ketoacidosis

Diabetic ketoacidosis is sometimes the first sign that a child has diabetes. It happens when the body does not have enough insulin to use glucose (the sugar) in the blood for fuel. The body then turns to its fat stores for energy. This process produces ketones as a by-product. Unfortunately, the ketones make the blood too acidic (ketoacidosis).

Symptoms of diabetic ketoacidosis include dehydration, vomiting, breathing fast, tiredness and confusion. You may notice that your child is more thirsty than normal and urinates more often (wees more).

Diabetic ketoacidosis is a medical emergency. Take a child straight to the emergency department if they are vomiting and are dehydrated.

Food allergy

food allergy is more likely to happen in the first year of life, when a new food is given to a child.

Cow’s milk allergy is an example of a food allergy that may cause vomiting as a symptom in children. One in 50 babies are allergic to cow’s milk. Most will outgrow it by the time they are aged 3 to 5 years. Symptoms include hives, vomiting and diarrhoea, swelling of the lips, face or eyes, and abdominal pain. These symptoms develop a few minutes to 2 hours after the child drinks the milk. If the allergic reaction is severe, the child may have anaphylaxis — a potentially life-threatening emergency. Symptoms of anaphylaxis include breathing difficulties, swelling of the throat, wheeze and collapse.

If you think a child is having a severe allergic reaction, call triple zero (000) for an ambulance.

Motion sickness

Motion sickness is more common in older children than babies. Car, train and air travel can cause it, as well as virtual reality games and amusement park rides.

How is vomiting diagnosed in children?

A doctor will want to determine how long your child has been vomiting. Has the vomiting been sudden, or has it been happening for a while?

They will want to examine your child, and they will assess whether there are any signs of dehydration.

Tests that may help determine the cause of the vomiting include:

If the vomiting has been going on for a little while, your doctor may suggest referring your child to a specialist, such as a gastroenterologist, an allergy expert, a neurologist or a paediatrician.

How is vomiting treated in children?

The majority of vomiting episodes in children are due to viral gastroenteritis, and can be treated with home care, as long as the child does not have dehydration or is a baby under 6 months. Babies under 6 months who have gastroenteritis should always be taken to the doctor.

How to look after a child with viral gastroenteritis at home

If the cause of vomiting is gastroenteritis or food poisoning, the focus should be on keeping your child hydrated and replacing any lost minerals and salts through oral rehydration solution, which is available from the pharmacy.  Mostly, these episodes will clear up without any specific treatment.

Vomiting caused by viral gastroenteritis usually clears up in 1-2 days, but diarrhoea goes on for longer.

Consider the following if you are caring for a baby or child with vomiting due to gastroenteritis, at home:

  • Breastfed babies over 6 months should continue to be breastfed, but more often. If they vomit, offer them a drink after each time. You can also offer them oral rehydration solution or water for the first 12 hours.
  • Bottle-fed babies should have their formula replaced with oral rehydration solution or water for the first 12 hours, then they can have normal formula in small amounts, more often than normal feeding. If they vomit, they should be offered a drink after every time.
  • Give older children small amounts of clear fluids to drink often — about every 15 minutes.
  • Oral rehydration solutions are strongly recommended for any child with frequent diarrhoea or vomiting.
  • Oral rehydration solution can be chilled or made into ice blocks for a child to suck, if they do not want to drink it.
  • Don’t give your child undiluted drinks high in sugar, such as sports drinks, lemonade or cordial, which can make diarrhoea or dehydration worse.
  • Children with gastroenteritis may refuse solid food, but it’s good for them to return to their normal diet as soon as possible, as long as they are not dehydrated or vomiting.
  • Do NOT give children antidiarrhoeal medicines or anti-vomiting medicines (antiemetics) — they may be harmful.
  • Make sure your child rests.
  • Don’t send them to nursery, daycare or school until they have not had a loose bowel motion for 24 hours.
  • If they have had norovirus, they should not go to nursery, daycare or school, until there hasn’t been any loose bowel motions or vomiting for 48 hours.

If a child is vomiting and has any of the following conditions, you should take them to the emergency department straightaway:

  • swollen or tender abdomen
  • stiff neck — with or without photophobia (pain when looking at bright lights)
  • high fever
  • blood in the vomit or in the stool (poo)
  • green-coloured vomit
  • vomiting early in the morning
  • projectile vomiting (where the vomit is ejected some distance)
  • bulging fontanelle in a baby
  • vomiting that isn’t stopping
  • can’t keep fluids down
  • signs of dehydration, such as fewer wet nappies, darker coloured urine, or dry lips and mouth

How is vomiting due to other causes treated in children?

Whatever the cause of vomiting, treatment needs to ensure that a child doesn’t develop dehydration because of the fluids lost when vomiting.

If your child becomes dehydrated they may need to go to hospital for rehydration via a nasogastric tube, which goes down their nose into their stomach, or intravenously on a drip.

Aside from avoiding or treating dehydration, any specific vomiting treatment will depend on the underlying cause.

Anti-vomiting medicines (antiemetics) are not generally recommended in children and may be harmful.

Surgery is usually needed for conditions such as appendicitis, bowel obstruction and pyloric stenosis, where there are blockages or problems in the digestive system.

Meningitis is treated in hospital. Treatment depends on how unwell your child is. Bacterial meningitis is treated with antibiotics. Your child may need steroids to reduce swelling on the brain. Viral meningitis is not helped by antibiotics.

Diabetic ketoacidosis will need to be treated in hospital. This involves safely reversing any dehydration, stabilising blood sugar levels with insulin and closely monitoring your child.

Infections, such as urinary tract infections, are usually treated with antibiotics.

Motion sickness in children can often be avoided with simple techniques. If these don’t work, children over 2 years may be able to try medicines. Talk to your doctor or pharmacist about what medicines may be suitable.

Can vomiting be prevented in children?

Gastroenteritis is the most common cause of vomiting in children. It is highly infectious and easily spread between people, especially children.

You can help minimise the spread of gastroenteritis by:

  • washing your hands regularly, especially after nappy changes and before feeding
  • washing your hands before food preparation and after going to the toilet
  • wearing gloves when cleaning up diarrhoea or vomit and sealing it in a plastic bag before putting it in the bin
  • practising good food safety
  • keeping your child away from nursery, day care or school until they have not had a loose bowel motion for 24 hours
  • getting your baby vaccinated against rotavirus

There are ways to prevent or minimise the risk of vomiting from other causes, depending on what they are. For example, vaccination is available on the Australian National Immunisation Program to protect against some causes of meningitis, including meningococcal and pneumococcal disease.

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