Is gastro contagious, and how long does it last? An Australian parent's guide
Quick answer
Yes, gastro (gastroenteritis) is very contagious. Most people are infectious from when symptoms start until about 48 hours after the last bout of vomiting or diarrhoea — though some viruses, like rotavirus, can spread for up to two weeks. Gastro usually lasts one to three days. Rest, regular fluids and good hand hygiene are the mainstays of looking after it at home.
Gastro can move through a household in a matter of hours, so the two questions parents ask most are simple: is gastro contagious, and how long does it last? This is an Australian parent's guide to the symptoms, the contagious period, how gastro spreads, and the simple steps that help you look after your family at home.
On this page Is gastro contagious? · How long does gastro last? · How long is gastro contagious for? · How does gastro spread? · Gastro symptoms · What to eat with gastro · Looking after gastro at home · Stopping the spread · When to see a doctor · FAQ
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Is gastro contagious?
Yes. Gastroenteritis — known as "gastro" or a "tummy bug" — is highly contagious. It is usually caused by viruses such as norovirus and rotavirus, and can also come from bacteria, parasites or contaminated food and water. It spreads easily between people, which is why it often passes quickly through families, childcare centres and schools.
The 48-hour rule: keep children home from school or childcare until 48 hours after their last episode of vomiting or diarrhoea.
How long does gastro last?
For most healthy children and adults, gastro lasts one to three days. Some people feel better within 24 hours; others take a little longer to get their appetite and energy back. Symptoms that last beyond a few days, or that come with warning signs like dehydration, are worth a call to your GP or 13HEALTH on 13 43 25 84.
| Stage | Typical timing |
|---|---|
| Incubation (catch it to first symptom) | 12 hours to 3 days |
| Main symptoms (vomiting, diarrhoea) | 1 to 3 days |
| Still contagious after recovery | At least 48 hours; rotavirus up to 2 weeks |
How long is gastro contagious for?
You are generally contagious from the moment symptoms appear until at least 48 hours after they stop. With rotavirus, the virus can be passed on from before symptoms begin through to around two weeks after recovery. That long tail is why hand hygiene matters even once someone feels well again.
How does gastro spread?
Gastro spreads through contact with the stool or vomit of an infected person — directly, or through contaminated hands, surfaces, food and water. It can also spread through airborne particles when someone is sick. Common routes include:
- Touching contaminated surfaces, taps, toys or door handles, then touching your face
- Preparing or sharing food without washing hands first
- Caring for or cleaning up after someone who is unwell
- Close contact in households, childcare and schools
Good hand hygiene is the single best way to slow gastro spreading at home.
Shop hand sanitiser →Gastro symptoms to watch for
Gastro symptoms usually come on quickly. A person may have one or several of these:
- Nausea and vomiting
- Diarrhoea
- Stomach cramps and abdominal pain
- Fever
- Headache, and muscle aches and pains
- Loss of appetite and tiredness
A fever often comes with gastro. Keeping an eye on temperature with a forehead thermometer helps you track how your child is travelling. For step-by-step guidance, see our guides on managing a fever in a toddler and what a normal baby temperature looks like.
What to eat (and drink) when you have gastro
Fluids matter more than food in the first day or two. The aim is to replace what is lost through vomiting and diarrhoea and to avoid dehydration.
- Drink small amounts often — water, clear broth, or oral rehydration solution from a pharmacy
- Ease back into food when appetite returns — plain options like toast, rice, crackers and bananas are gentle on the stomach
- Go easy on very fatty, sugary or spicy foods until you feel better
- For babies, continue breast or bottle feeds and offer them more often; ask your pharmacist about rehydration products suited to infants
Looking after gastro at home
Most gastro can be managed at home with rest and fluids. Comfort measures that help:
- Keep the person resting and hydrated with frequent small drinks
- Keep an eye on temperature with a thermometer so you can see any change
- For fever comfort, a fever cooling patch gives a cooling sensation on the forehead — it is for comfort and does not lower a temperature. See our guide on how to use a fever cooling patch
- Keep a stocked first aid kit on hand so the essentials are ready before anyone gets sick
Fever cooling patches for forehead cooling comfort while a tummy bug runs its course.
Shop fever cooling patches →How to stop gastro spreading at home
A few simple hygiene habits cut the risk of gastro passing to the rest of the family:
- Wash hands with soap and water for at least 20 seconds — after the toilet, after caring for someone unwell, and before handling food
- Use an alcohol-based hand sanitiser between handwashing when soap and water aren't available
- Keep anyone with symptoms home until 48 hours after their last episode
- Clean contaminated surfaces with hot water and detergent, then disinfect
- Wash soiled clothes and bed linen separately, straight away
- Don't share towels, cups or cutlery while someone is unwell
In Australia, babies are offered free rotavirus immunisation as part of the National Immunisation Program. Ask your doctor or maternal and child health nurse for details.
When to see a doctor
Gastro is usually mild, but seek medical advice promptly if you or your child have any of these signs. Babies, older people and anyone with a weakened immune system can become unwell more quickly.
- Signs of dehydration — very few wet nappies or little urine, dry mouth, no tears, sunken eyes, drowsiness
- Blood in vomit or stool
- Persistent stomach pain, or a high fever that won't settle
- Vomiting or diarrhoea lasting more than a couple of days
- A baby under six months with gastro symptoms
For around-the-clock advice you can call your GP or 13HEALTH on 13 43 25 84, or in an emergency call 000. See also our guide on when to take your child to hospital with a fever.
Gastro FAQ
Is gastro contagious before symptoms start?
Yes, it can be. With some viruses such as rotavirus and norovirus, a person can pass on the infection shortly before symptoms appear and for some time after they recover, which is why hand hygiene matters even when people seem well.
How long should you stay home with gastro?
Stay home — and keep children away from school or childcare — until 48 hours after the last episode of vomiting or diarrhoea. This is the standard Australian guidance to avoid passing gastro on to others.
How is gastro spread?
Through contact with the stool or vomit of an infected person — via contaminated hands, surfaces, food and water, or airborne particles when someone is sick. Washing hands and cleaning surfaces are the best defences.
What should you eat when you have gastro?
Focus on small, frequent drinks first — water, clear broth or oral rehydration solution. As appetite returns, plain foods like toast, rice, crackers and bananas are gentle on the stomach. Go easy on fatty, sugary and spicy foods until you feel better.
Can you have gastro without vomiting?
Yes. Some people have mainly diarrhoea, stomach cramps and nausea without much vomiting. Symptoms vary from person to person and from one bug to another.
This article is general information for Australian families and is not a substitute for medical advice. If you are worried about yourself or your child, contact your GP or 13HEALTH on 13 43 25 84. Sources: NSW Health, healthdirect Australia, The Royal Children's Hospital Melbourne, Raising Children Network.