Gastro in kids: how to keep them hydrated and when to worry

Baby & child ·Published 10 October 2026 ·Reviewed 10 October 2026

Written by the Priceline Pharmacy Pacific Fair team. Reviewed by Jason Markey, BPharmSci, MPharm, Owner and Pharmacist.

General health information from a registered pharmacist. It doesn’t replace advice from your own pharmacist or doctor.

When your child has gastro, the most important job is getting fluids into them: small amounts, often, even if they’re vomiting. Oral rehydration solution is the best choice because it replaces salts as well as fluid, and it can be frozen into ice blocks for a reluctant toddler. Keep breastfeeding or formula feeding, and see a doctor if your baby is under 6 months old.

Most children with gastro can be cared for at home. Below we cover how much to give, what to avoid, the warning signs to watch for, and Queensland’s rules on returning to childcare or school.

What are the signs of dehydration?

Dehydration happens when the body loses more water than it takes in, and young children and babies are most at risk. The RCH groups the signs by how serious they are:

• Mild: your child is thirsty and weeing less than usual.
• Moderate: they have a dry mouth, lips and tongue.
• Severe: they have sunken eyes, cold hands and mottled (patchy, reddish-blue) skin.

In babies, Children’s Health Queensland says to watch for less than half the usual number of wet nappies, or drier nappies, dark-coloured wee, and cool, mottled or greyish skin with drowsiness. Severe dehydration needs a hospital straight away.

How much fluid should I give, and how often?

Little and often is the rule. The RCH’s fact sheets give these guides:

A few tips that help:

• If your child won’t drink from a cup, the RCH suggests giving fluid with a syringe, the same way you give medicine.
• Make up oral rehydration solution exactly as the pack says. Children’s Health Queensland warns that stronger or weaker solutions may disrupt body salt levels and harm your child.
• Children often don’t like the salty taste. healthdirect suggests chilling oral rehydration solution or freezing it into ice blocks to suck, and the RCH says a regular icy pole is fine if they won’t take juice or oral rehydration solution.

Which drinks should I avoid?

• Undiluted sugary drinks. healthdirect says not to give undiluted drinks that are high in sugar, such as sports drinks, lemonade or cordial, as they can make diarrhoea or dehydration worse. The RCH adds ginger ale to that list.
• Full-strength juice. If you use apple juice, dilute it half and half with water.
• Lots of plain water on its own. Children’s Health Queensland says water by itself in large amounts isn’t recommended.
• Watered-down formula. Keep formula at normal strength.

What about food and medicines?

When can my child eat again?

The RCH says there are no specific dietary restrictions during or after gastro. Offer food again when your child feels like eating, which is usually once the vomiting has stopped. Raising Children suggests not stopping food for more than 24 hours, and starting with bland foods like plain crackers, bread, rice or potato.

Should I give medicine for gastro?

Medicines that stop vomiting or diarrhoea aren’t the answer for children. The RCH says over-the-counter medicines that reduce vomiting and diarrhoea may be harmful for children, and healthdirect says anti-diarrhoeal medicines should not be used to treat diarrhoea in children. If vomiting is a real problem, a doctor can decide whether a prescription anti-nausea medicine is needed.

Paracetamol can help if your child is in pain (RCH). Don’t give aspirin. Ask our pharmacist before giving ibuprofen to a child who is dehydrated, and see our guide to paracetamol and ibuprofen for kids for doses.

How do I stop gastro spreading?

Gastro is very contagious, so the whole household needs to pitch in.

• Wash hands with soap and water, especially after the toilet or a nappy change and before preparing food or eating. Children’s Health Queensland notes that alcohol sanitiser will not kill the infection.
• Wear gloves when cleaning up vomit or poo. The RCH suggests a mask too. healthdirect advises sealing the mess in a plastic bag before it goes in the bin.
• Wash or disinfect toys, clothes and bedding regularly (RCH).
• Don’t share cups, drink bottles or cutlery (Raising Children).
• Skip the pool for a while. The RCH says children shouldn’t go back to swimming for two weeks after recovering, to help stop the spread. That’s worth knowing before swimming lessons or a day at the water park.

When can my child go back to childcare or school in Queensland?

Queensland Health’s Time out poster (last revised January 2026) says a child with diarrhoea and/or vomiting should stay home until they have had none for at least 24 hours. For norovirus, it’s at least 48 hours. Brothers and sisters without symptoms don’t need to stay home, and anyone who prepares or serves food should stay away from that work until they’ve had no symptoms for 48 hours. The poster also says children should be well before they return.

Some health services suggest a longer break. The RCH says to wait until there’s been no diarrhoea or vomiting for 48 hours, and Children’s Health Queensland suggests 48 hours since the last diarrhoea. Your centre or school may also have its own policy, so check with them.

How our pharmacists can help

Our pharmacists can help you choose an oral rehydration solution, show you how to make it up, check whether a medicine is suitable for your child’s age, and tell you when it’s time to see a doctor. You can browse the children’s medicine range on priceline.com.au, or talk to our pharmacists at Pacific Fair, no appointment needed.

When to see a pharmacist or GP

See a GP (our in-store Help Medical GPs are one option) if:

• your baby is under 6 months old and has gastro symptoms, especially vomiting or a fever
• your child is vomiting, has diarrhoea and isn’t drinking enough
• you notice signs of dehydration, such as fewer wet nappies, dark wee or a dry mouth
• they have constant tummy pain that is getting worse or isn’t helped by paracetamol
• diarrhoea lasts more than 10 days
• they picked up the illness overseas

Go to the nearest emergency department if your child:

• can’t keep any fluids down
• has green vomit, or blood in their vomit or poo
• has more than 8 watery poos in a day
• is under 3 months old and is vomiting with a fever
• is fussy or drowsy, or has signs of severe dehydration

For non-urgent advice, you can call 13 HEALTH (13 43 25 84) to speak to a registered nurse.

Call 000 in an emergency. If your child is unconscious, very lethargic or hard to wake, call triple zero (000).

This article is general information only and isn’t a substitute for personal advice from your doctor or pharmacist. Always read the label and follow the directions for use. If symptoms persist or you’re worried, talk to your pharmacist or GP. In an emergency, call 000.