The most common cause of vomiting in both adults and children is gastroenteritis, which is commonly known as 'gastro' or tummy bug. Other causes include food allergy, poisoning, reflux, meningitis, overeating, stress, infection or illness.
There are many things which can cause vomiting in children. Some of the causes, and the other symptoms you may see with them, are described below.
Vomiting + diarrhea + mild fever
- Also called gastro or tummy bug, it is the most common cause of vomiting and diarrhoea in adults and children.
- Gastroenteritis can be caused by viruses (such as rotavirus), bacteria (such as Campylobacter or E. coli which can cause food poisoning) or parasites (such as giardia).
- Read more about gastroenteritis.
Nausea + vomiting + rash
- Symptoms of food allergy can occur within minutes or hours of eating a certain food.
- Call 111 immediately if your child has shortness of breath or swelling of the mouth or throat. An extreme allergic reaction can be fatal if you don't act fast.
- Read more about food allergy.
Eating or drinking something poisonous
If you think your child has swallowed a poison, follow these steps:
- If they are awake, call the New Zealand National Poisons Centre(external link) on 0800 POISON (0800 764 766).
- If they are sleepy or unconscious, lie them on their side and dial 111 for an ambulance.
- Do NOT try to make your child vomit or give them food or liquid until you have been given advice.
Vomiting + high fever + piercing scream (babies) or stiff neck (older children)
- This is a potentially serious brain infection which since the development of the Haemophilus influenzae type b (Hib) vaccine is now rarely seen.
- See your doctor straight away if your baby is vomiting, running a fever, and irritable, or if your older child is vomiting and complains of a stiff neck or seems dizzy and confused.
- Read more about meningitis.
Reflux / spilling
Bringing up milk after a feed is sometimes mistaken for vomiting. The main difference is that vomiting is an effortful process while reflux or spilling is effortless. For babies less than 1 year old, spilling is a normal process that helps to relieve an uncomfortably full stomach. Read more about reflux.
Other causes include:
- Eating too much – especially rich food that they do not normally eat a lot of (for example sweet or fatty foods)
- Being very worried, anxious or stressed (this is more common in older children and adults)
- Having a gut obstruction - vomit in this case is usually greenish-looking
- Being sick with the flu or other illness
- Having an infection, such as appendicitis.