What is gastroenteritis?

Gastroenteritis is an illness that affects your gut (stomach and intestines).

Gastro may be caused by:

• viruses (such as rotavirus or norovirus infections)
• bacteria (including salmonella)
• toxins produced by bacteria
• parasites (such as giardia)
• chemicals (such as toxins in poisonous mushrooms)

Gastro should only last for a few days. It doesn’t usually require medication.

It is very important to drink plenty of fluids. Older people, young children and those with a weakened immune system are at risk of developing more serious illnesses.

See a doctor immediately if your child cannot keep down a sip of liquid or has dehydration (dry mouth, no urine for 6 hours or more, or lethargy).

Gastroenteritis symptoms

Someone with gastroenteritis may have:

• vomiting
• diarrhoea
• nausea (feeling sick in the stomach)
• stomach pains
• fever
• headaches
• no appetite

Check your symptoms using healthdirect’s online Symptom Checker to get advice on when to seek medical attention.

Gastroenteritis diagnosis

If you are unwell with diarrhoea or vomiting, you could have gastro. A doctor can diagnose gastro after talking to and examining you. If you’re not getting better, the doctor may want to do stool (poo) tests to find out what's making you ill.

Gastroenteritis treatment

The most important treatment for gastroenteritis is to drink fluids. Frequent sips are easier for young children than a large amount all at once. Keep drinking regularly even if you are vomiting.

If you have a baby or young child with gastro, it’s a good idea to have them checked by a doctor for dehydration. You can get rehydration fluids from a pharmacy. These are the best fluids to use in cases of gastro, especially for children.

If you can’t get any, or your child refuses to drink it, giving diluted fruit juice (one part juice to four parts of water) is reasonable. You could try a cube of ice or an iceblock if your child won’t drink. Avoid milk and other dairy products and do not give juice, sodas, sports drinks or other soft drinks as the sugar may make the diarrhoea worse. It is fine to eat once you feel like it.

It's fine to eat once you feel like it.

Babies can continue milk feeds throughout the illness, with rehydration fluid between feeds. Medication for nausea or diarrhea can be useful for adults, but may not be safe for kids. Antibiotics are rarely helpful.

If you are very sick with gastro, you may need to go to hospital where you may be put on a drip.

How is gastroenteritis spread?

Infectious gastro can be spread very easily. You might get it from having contact with an infected person (or their vomit or poo). It can also spread via contaminated food or water.

Gastroenteritis prevention

To reduce your risk of catching or spreading gastro, wash your hands well after using the bathroom or changing nappies, and before preparing or eating food.

If you have gastro, it’s important to stay home (away from work, school or childcare) until the symptoms have been gone for at least 24 hours. If your work involves handling food or looking after children, the elderly, or patients, do not return to work until 48 hours after the symptoms have stopped.

You can find more information on gastro in kids on the GESA (Gastroenterological Society of Australia) website.

Children and vaccination for rotavirus

Rotavirus is a virus that causes severe gastroenteritis in babies and young children. All young children should receive the rotavirus vaccine at about 2 months and 4 months of age. A third dose at 6 months may be needed depending on the brand of vaccine used.

This vaccine is effective in preventing the rotavirus infection in about 7 out of every 10 children vaccinated. It is also effective in preventing severe gastroenteritis in about 9 out of every 10 infants vaccinated. The vaccine provides protection for up to 5 years.