Gastroenteritis Symptoms: How Long Gastro Lasts and When to Get Help

Gastroenteritis, or gastro, is a bowel infection that causes vomiting and diarrhoea. Most people recover with rest and fluids, but dehydration can be serious, especially for young children and older people.

What are the symptoms of gastroenteritis?

Nausea and vomiting
Diarrhoea
Stomach pain and cramps
Fever
Body aches, weakness and tiredness
Headache and loss of appetite

How long does gastro last?

Vomiting usually lasts 1 to 2 days. Diarrhoea usually lasts 1 to 3 days, but it can last up to 10 days.

What causes gastro?

Viruses, such as rotavirus and norovirus, are the most common cause. Bacteria, bacterial toxins and parasites can also cause it. It spreads through contact with infected vomit or faeces, contaminated food, drinks or objects, and contact with other people.

What should I drink and eat?

Sip clear fluids every 5 to 10 minutes to prevent dehydration, and avoid sugary drinks, which can worsen diarrhoea. When you feel hungry, try simple foods like crackers, rice, clear soup, banana or dry toast. Rest, and keep breastfeeding as normal.

Can I take medicine for gastro?

Check with a doctor before taking anti-nausea or anti-diarrhoea medicines. Do not give anti-diarrhoea medicines to children, and ask a doctor or pharmacist before giving any medicine to babies or young children. Viral gastro does not need antibiotics.

What are the signs of dehydration?

In adults: passing little or no urine, dark or smelly urine, or feeling faint or dizzy when standing.

In children: being very sleepy or drowsy, very thirsty, fewer than 4 wet nappies a day, cold hands and feet, dry lips and tongue, sunken eyes or fontanelle, or fast breathing.

When should adults see a doctor?

See a doctor for stomach pain that is getting worse, frequent vomiting or diarrhoea, blood or mucus in your poo, fever, signs of dehydration, or any symptoms that worry you.

When should children see a doctor?

Babies under 6 months should always see a doctor if gastro is suspected.
Children under 3 with a fever over 38°C should see a doctor.
Children under 8 kg, children born prematurely, and those with other health problems should also see a doctor.
Seek care if a child has blood in their poo, dark green vomit, severe stomach pain, or cannot keep food or fluids down.

How do I stop gastro spreading?

Stay away from school or work until 48 hours after your last vomiting or diarrhoea.
Wash your hands with soap and water after using the toilet, changing nappies or cleaning up, and before eating or preparing food.
Do not prepare food for others while sick.
Wash contaminated clothing and bedding in hot water with detergent.
Clean bathrooms and toilets often.
Do not share towels, cups, cutlery or toothbrushes.

Call triple zero (000) if you need urgent medical help. For health advice, call Healthdirect on 1800 022 222.

Source: Healthdirect: Gastroenteritis.

General education does not replace individual medical advice. Updated November 2026.

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