Gastroenteritis (gastro) is an infection of the bowel that may cause diarrhoea (runny, watery poo), vomiting or both. It is common and easy to catch, easy to spread and often occurs in outbreaks. Particularly at school, daycares or within the family vomiting usually settles quickly but diarrhoea can last up to 10 days. Gastroenteritis can be caused by viruses, bacteria or parasites.

Signs and symptoms

• Vomiting for 2-3 days
• Diarrhoea for up to 10 days
• Fever
• Tummy pain
• Dehydration

Dehydration

Young children (especially under 6 months of age) are at high risk of dehydration and must be watched very carefully. You will know your child is dehydrated if they:

• have less than half the usual number of nappies every day or drier nappies
• have cool, mottled or greyish skin and are drowsy
• are not going to the toilet a lot and have dark-coloured wee
• feel light-headed or dizzy or have dry lips and mouth.

Treatment

Preventing dehydration is the main treatment. It is very important to replace any fluids your child loses by vomiting or diarrhoea. Children with severe dehydration may need to stay in hospital so they can be given fluids through their arm (via a tube into a vein) or their nose (a tube down the nose).

Medicine to stop diarrhoea is not recommended and antibiotics are rarely needed. Your doctor will let you know what treatment is needed for your child.

Care at home

Give your child sugar-based fluids to help them get enough fluid. Give your child small sips (as this is less likely to be vomited back up) using a syringe, spoon or cup. You can also give apple juice (diluted 50:50 with water) or ice blocks.
If your child is breastfeeding smaller feeds, more often, will help them stay hydrated.

Oral rehydration solutions such as Gluco-lyte, Gastrolyte, HYDRAlyte, Repalyte and Pedialyte can also be used to help your child. Follow the dosage instructions exactly. Stronger or weaker solutions may disrupt body salt levels and harm your child.

Water by itself in large amounts is not recommended as it does not contain the sugars and salts your child needs.

For non-urgent medical advice, call 13 HEALTH (13 43 25 84) to speak to a registered nurse 24 hours a day, seven days a week for the cost of a local call.

Ask for an interpreter if you need one.

When can my child start eating food again?

For older children, start giving them solid food within 24 hours. This may help reduce how long the diarrhoea lasts. Start with bland foods like plain pasta, boiled rice or potato, dry toast or plain biscuits.
If your child is less than 12 months old, reintroduce their usual milk formula after 24 hours. Do not water down the formula.

Stop the spread

• Gastroenteritis is highly infectious so keep your child away from other children as much as possible until they are well or 48 hours since the last diarrhoea.
• Wash your hands well with soap and water particularly before eating or preparing meals, and after changing dirty nappies. Alcohol sanitiser will not kill the infection.
• Change your baby’s nappies frequently and use a zinc-based bottom cream to stop the diarrhoea from burning your child’s skin and causing a nappy rash.

When to seek help

If your child has seen a doctor but the symptoms are getting worse, go back to your doctor for further advice. See your GP if your child has had diarrhoea that continues for more than 10 days.

Take your child to the nearest emergency department if they:

• are less than 3 months, vomiting (with or without diarrhoea) and have a fever
• are vomiting frequently and can’t keep any fluid inside, especially if they are less than 6 months of age
• have more than 8 watery poos per day
• have less than half the number of wet nappies they usually have or significantly drier nappies with fewer wet nappies
• have severe stomach pain
• bring up green vomit
• have blood in their vomit or poo
• have severe neck or head pain
• are fussy or drowsy
• may have swallowed a button battery.

In an emergency, call Triple Zero (000) and ask for an ambulance.

If you're not sure whether to go to an emergency department, call 13 HEALTH (13 43 25 84) and speak to a registered nurse.

Developed by the Emergency Department, Queensland Children’s Hospital. We acknowledge the input of consumers and carers.

Resource ID: FS153. Reviewed: July 2022.

Disclaimer: This information has been produced by healthcare professionals as a guideline only and is intended to support, not replace, discussion with your child’s doctor or healthcare professionals. Information is updated regularly, so please check you are referring to the most recent version. Seek medical advice, as appropriate, for concerns regarding your child’s health.