Vomiting in children: what to watch and when to see a doctor

Vomiting frightens parents more than most symptoms, and with good reason: small children lose fluid quickly. But vomiting itself is not a diagnosis. It happens with gut infections, with ordinary respiratory infections that bring a high fever, with food poisoning, with motion sickness — and sometimes it points to a condition that needs urgent care.

What to assess first

• Ability to drink: is the child keeping down small amounts of fluid.
• Passing urine: how often and how much — the most practical thing to track at home.
• General condition: activity, response to you, ability to settle.
• Other symptoms: diarrhoea, fever, tummy pain, headache, rash.
• How often the vomiting happens and how long it has lasted, and its trend: less or more often than a few hours ago.

Age: why the threshold is lower in babies

The younger the child, the faster dehydration develops and the less obvious the outward signs. In the first months of life it is important to tell ordinary posseting — a small amount brought up after a feed — from true vomiting. Repeated forceful vomiting after every feed in a baby, especially with poor weight gain, needs a doctor's assessment rather than watchful waiting.

How to give fluids when a child is vomiting

The main principle is often and in very small amounts. A large volume drunk at once usually triggers another episode, and the parent concludes that “nothing stays down”. A small amount every few minutes is tolerated noticeably better.

• Start with very small amounts and increase the volume as the vomiting becomes less frequent.
• Oral rehydration solutions are used to replace losses; which solution and how much of it your child needs is best confirmed with a doctor or a pharmacist — homemade mixtures are not recommended.
• A breastfed baby continues to be breastfed, more often and in shorter feeds.
• Do not force food: a few hours without eating is not dangerous; refusing to drink is.

When vomiting is not a gut infection

Assuming every episode of vomiting is “food poisoning” or “rotavirus” is a common and unsafe mistake. There are situations where vomiting is only one of the symptoms and the cause lies elsewhere:

• vomiting without diarrhoea but with worsening tummy pain — a doctor must rule out surgical causes;
• vomiting after a head injury — assessed without delay;
• vomiting with a severe headache, light sensitivity, unusual drowsiness, or a rash that does not fade when pressed;
• vomiting in a child with a high fever and no gut symptoms — this is sometimes how a urinary tract infection or another infection presents;
• vomit containing blood or green material;
• repeated vomiting in a baby with poor weight gain.

That is why the list of warning signs on this page includes items that have nothing to do with the gut: vomiting is a general symptom, and its cause is determined by an examination.

Vomiting together with diarrhoea and fever

This combination is typical of an acute gut infection. It also means the fastest fluid loss, so monitoring should be closer: offer drinks more often and watch urination and activity more carefully. The signs of fluid loss are covered in detail in the dehydration article.

This page is for general information only and is not a substitute for a consultation with a doctor. A child's diagnosis and treatment are determined by a doctor during an examination.