What you need to know

  • Diarrhoea is when you have frequent, loose or watery poo. 
  • It's usually caused by a viral, bacterial, or parasitic infection. Typically, it will improve after a few days but it can last up to 10 days. 
  • Medicine is not usually needed and the main treatment is to provide more fluids for your child so they don't get dehydrated.
  • Take your child to the doctor, if they are under six months old (young babies can get sick quickly), or if your little one is showing any signs of dehydration. 


The most common cause of diarrhoea is a viral infection, but it can also be caused by: 

  • a bacterial infection 
  • contaminated food and water 
  • a reaction to food
  • infection in other parts of the body.


Fluid or runny poos, with or without the following symptoms: 

  • feeling unwell 
  • not interested in eating and drinking  
  • painful stomach cramps 
  • bloating 
  • farting 
  • feeling weak
  • fever
  • vomiting (which usually starts before the diarrhoea). 

Your little one’s symptoms will usually settle down after a few days, but can last up to 10 daysIf symptoms continue for longer or you are worried, call PlunketLine or your doctor.  

Caring for your child at home

Medicine is not usually needed and the main treatment is to provide more fluids for your child to help them replace lost fluidsIt’s usually better to give small drinks often, rather than large drinks less often. 

If your child doesn’t want to drink and is vomiting often and/or has a lot of diarrhoea, they can become dehydrated and need to be checked by a doctor. 

Treatment for a baby  

It’s important to keep breast or bottle feeding your child and offer extra fluidsOffer your baby food and fluids from their normal diet if theyve started to eat solids. Your baby may not be hungryso follow their cues as to how much they eat, as drinking is the most important. 

Treatment for an older child 

Make sure your child keeps up their fluids, as kids can quickly become dehydrated. Water is generally the best choice, but they may also be interested in drinking milk. Try to avoid fizzy or sugary drinks like fruit juice or sodas. 

Your child may not be as hungry as usual so offer them small amounts of food from their normal diet, bland non-greasy foods are ideal. Try to avoid grains, sugary or fatty foods.  

When to visit the doctor

Your child should see a doctor if they: 

  • are six months old or younger 
  • are vomiting and have diarrhoea, especially if they're not drinking much 
  • have a lot of diarrhoea (eight to 10 watery bowel motions, or two or three large motions per day) 
  • have diarrhoea that hasn't improved after 10 days, or is getting worse 
  • can’t keep fluids down 
  • show signs of dehydration, including 
    • dry lips, mouth and tongue 
    • sunken eyes 
    • cold hands and feet 
    • unusual sleepiness or lack of energy 
    • fewer wet nappies 
    • not passing as much wee as usual or passing a small amount of dark yellow wee 
  • develop severe stomach pains or a swollen tummy 
  • have poos that contain blood or smell really bad  
  • have blood or bile (greenish fluid) in the vomit 
  • have yellow skin and the whites of their eyes turn yellow 
  • make you worry for any other reason. 

Ministry of Health

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The Government's principal advisor on health and disability: improving, promoting and protecting the health of New Zealanders.