Gastroenteritis factsheet
Introduction
Gastroenteritis, or gastro, is a common illness in infants and children. It happens when your child’s digestive system, including the stomach and intestines, becomes infected.
Infection can be caused by:
- viruses like rotavirus or norovirus
- bacteria like salmonella or E-coli
- parasites like giardia.
Gastroenteritis spreads quickly through contact with:
- vomit
- poo
- fluids from coughing and sneezing
- food or drink that is contaminated with bacteria or parasites.
Children and babies are more at risk of getting and spreading gastroenteritis, and it can be more common in the winter months.
Signs and symptoms
Gastroenteritis usually starts with vomiting, followed by frequent, watery poos called diarrhoea.
Your child may also have:
- tummy pain
- fever
- a runny nose
- a sore throat.
See your local doctor as soon as possible if your child shows symptoms of a more severe infection, including:
- dehydration – losing fluids faster than your child can take them in
- throwing up fluids immediately after drinking
- continuous vomiting
- being very tired or drowsy
- blood or mucus in their poo
- ongoing tummy pain
- high fevers
- unexpected symptoms like pain when urinating or headaches.
Babies under six months old who have symptoms should be seen by a doctor as soon as possible.
If your child's vomit is green, call triple zero (000) for an ambulance or go to your nearest emergency department. Green vomit could be a sign of bilious vomiting, which can be life-threatening.
Diagnosis
Your child’s doctor can diagnose Gastroenteritis based on their symptoms.
Treatment
Most children with gastroenteritis will recover quickly.
Treatment will depend on:
- how old your child is
- how severe their symptoms are
- any other health conditions they have
- whether they are dehydrated.
Management
Fluids
Treatment for gastroenteritis will mainly focus on preventing dehydration when your child loses fluids from vomiting and diarrhoea.
You should encourage your child to drink fluids, even if they are vomiting. Depending on your child’s age, this may include:
- water
- oral rehydration fluids
- breastmilk
- infant formula.
Some children may be able to take medication that can stop vomiting, but medication to stop diarrhoea is not recommended.
Speak to your local doctor or pharmacist for more information.
Oral rehydration fluids
Oral rehydration fluids are available from your local pharmacy or supermarket.
They are specially made to replace:
- fluids
- carbohydrates
- electrolytes like sodium and potassium.
Oral rehydration fluids can come in different flavours and forms, including:
- sachets or concentrated liquid to mix with water
- tablets to dissolve in water
- ice-blocks
- ready to drink bottles.
Follow the instructions on the package closely to ensure your child gets the right amount of fluids.
If you don’t have oral rehydration fluids at home, you can use things like apple juice. When using fluids like juice, make sure they are watered down.
Avoid fluids that are fizzy or high in sugar or soft drinks, as these can make dehydration worse.
Amount of fluids to give
Babies and children who are vomiting may not want to drink. They may feel unwell, or they may vomit soon after drinking.
To prevent dehydration, try to give your child at least 5 mL of fluid per kg of body weight every hour.
For example:
- babies under 10kg - 60mL, given in 5ml doses every 5 minutes
- toddlers 10 - 20kg - 90mL, given in 7.5mL doses every 5 minutes
- primary school-aged children around 20kg - around 120mL every hour
- older children, over 30kg – around 180mL every hour.
Remember to be patient when giving fluids to your child. Offer small sips more often and, if possible, encourage them to sip after vomiting.
Babies and toddlers who are still breastfeeding can continue to be offered feeds. They may need to have fluids given with a medicine syringe, but older children may be able to sip on their own.
If your child can keep fluids down, slowly increase the amount they sip and reduce the frequency.
Fluids for babies under six months
Babies under six months with gastroenteritis should continue breastfeeding or formula feeding. See your local doctor or go to your nearest emergency department as soon as possible.
Fluids for babies and children over six months
Babies over six months who have gastroenteritis can have small amounts of water or oral rehydration fluids along with their breast milk or infant formula.
Do not add water to breast milk.
Do not add more water than needed to infant formula.
If your baby is breastfeeding, you should:
- continue breastfeeding or offering expressed milk on demand or at least every 2 hours
- offer water or oral rehydration solution with a syringe in between breastfeeds
- not give them solids while they are vomiting.
When the vomiting has stopped or after 24 hours, you can:
- continue to breastfeed or offer expressed milk on demand or every 2-3 hours
- offer water or oral rehydration solution with a syringe in between feeds
- re-introduce simple foods like rice cereal or vegetable puree, even if their poo is still runny.
If your baby is formula-fed, you should:
- replace formula with oral rehydration fluids for the first 12 hours
- resume normal infant formula after 12 hours in smaller, more frequent amounts
- continue feeding every 2-3 hours or on demand
- re-introduce simple foods like rice cereal or vegetable puree, even if their poo is still runny.
Food
Once vomiting has settled down or stopped, your child may be able to have simple foods that are easy to digest. Depending on the types of solids your child is eating, this might include:
- bananas
- rice
- toast
- soft or pureed fruit or vegetables.
You can offer these foods even if your child is still having diarrhoea.
Do not let your child go without food for more than 24 hours.
Management
Lactose intolerance after gastroenteritis
Occasionally, children can develop lactose intolerance after gastroenteritis. This can cause them to have a longer period of diarrhoea and stomach upset.
Lactose intolerance is a sensitivity to the sugars found in dairy products like:
- cows milk
- cheese
- yogurt
- some types of infant formula.
Speak to your local doctor if your child has any stomach issues from dairy products after gastroenteritis.
Preventing the spread
Gastroenteritis spreads quickly in children. Remember the following when your child has gastroenteritis to reduce the spread.
Hand hygiene:
- wash your hands thoroughly with soap before and after:
- touching your child
- feeding your child
- changing your child’s nappy
- cleaning up vomit and diarrhoea.
- wash and dry your hands after using the bathroom and before eating or preparing food.
Staying home:
- keep your child away from other children until the diarrhoea stops
- check with your school or daycare provider about their rules for vomiting and diarrhoea.
Cleaning and Laundry:
- wash clothing or bedding that is dirty with vomit or diarrhoea on a hot wash cycle
- clean bathrooms and toilets where there is vomit and diarrhoea regularly with disinfectant
- avoid sharing towels, face washers, toothbrushes, drinkware, or cutlery.
Food Handling:
- avoid preparing or handling food for other people while sick
- wash hands with soap before and after handling food.
