Emergency Care Institute Patient Fact Sheet

Published on 6 Jul 2022 Printed on 9 Feb 2023


This fact sheet is for people who have presented to the emergency department with this condition.

This fact sheet provides general information. If you have specific concerns, speak to your healthcare professional for further information and advice.

What is gastroenteritis?

Gastroenteritis – or gastro – is a gut infection caused by viruses, bacteria or other microbes. Gastroenteritis causes diarrhoea and vomiting that can lead to dehydration. Mild dehydration is common and is usually reversed by drinking fluids.


These are the main symptoms:

  • diarrhoea – at least three times in 24 hours
  • vomiting – at least three times in 24 hours
  • abdominal pain
  • high temperatures
  • dehydration.

Symptoms of dehydration in adults include:

  • tiredness or feeling thirsty, weak and irritable
  • dizziness or light-headedness
  • headaches
  • muscle cramps
  • passing small amounts of urine
  • passing darker yellow urine.

Symptoms of severe dehydration in adults include:

  • weakness or confusion
  • reduced level of consciousness
  • rapid heart rate
  • low blood pressure.

Severe dehydration is a medical emergency. Seek immediate medical attention.

Note: if you are on a fluid restriction plan see your doctor before you change your safe fluid intake plan.


The main treatment for gastroenteritis is to drink a lot of fluid and wait for symptoms to ease.

How much should I drink?

  • As a rough guide, drink at least one cup of liquid after each bout of diarrhoea to replace the fluid you have lost.
  • This extra fluid is on top of the amount that you would usually drink. For example, an adult will drink about two litres (eight cups) a day – more on hot days.
  • If you have vomited, wait five to 10 minutes, then drink slowly. For example, a sip every two to three minutes.
  • You will need to drink even more if dehydrated. A doctor will tell you how much to drink.

What fluid should I drink?

  • Most adults should drink water or rehydration drinks.
  • Drinks that contain a lot of sugar can sometimes make diarrhoea worse.
  • Rehydration drinks are made from sachets or you can buy pre-made drinks. They provide a good balance of water, salts and sugar. Some examples are Gastrolyte, Hydralyte and Repalyte. They may be available in the form of icy poles.

What foods can I eat?

  • Eat as normally as possible. Start with plain foods, such as wholemeal bread and rice.
  • Eat small, light meals as soon as you are able.
  • Be guided by your appetite.
  • Avoid fatty, spicy or heavy food at first.

Prevent the spread of gastroenteritis

Gastroenteritis is easily passed on from person to person. If you have gastroenteritis, follow this advice to prevent the spread of infection:

  • After going to the toilet, wash your hands with soap and water. Dry them well.
  • Don't share towels and wash cloths.
  • Don't prepare or serve food for others.
  • Regularly clean toilets you use with disinfectant.
  • At least once a day, wipe the flush handle, toilet seat, bathroom taps, surfaces and door handles with hot water and detergent.
  • Keep a cloth only for cleaning the toilet. Or use a disposable cloth each time.
  • Stay home from work or school for at least 48 hours after the last episode of diarrhoea or vomiting.
  • Ensure good food hygiene through proper storage, preparation, and cooking of food.

What to expect

Seek medical advice if:

  • you suspect that you are becoming more dehydrated
  • you have severe abdominal pain or an on-going high temperature
  • you have blood in your diarrhoea or your vomit
  • your symptoms are not settling or are getting worse (you vomit for more than one to two days or have diarrhoea that continues after three to four days)
  • you are elderly
  • you have an underlying health problem, such as diabetes, epilepsy, inflammatory bowel disease or kidney disease
  • you have a weakened immune system due to reasons such as, chemotherapy, long-term steroid treatment or HIV.

Also seek medical advice if you have any other symptoms that concern you.

Seeking help

In a medical emergency call an ambulance – dial triple zero (000). If you have any concerns, see your local doctor or healthcare professional. If this is not possible return to the emergency department or urgent care centre.

For more information

Ask your local doctor or healthcare professional. You can also call healthdirect 24 hours a day on 1800 022 222 or visit healthdirect.gov.au.

Evidence informedBased on rapid evidence check of grey literature, and where there is no research, based on clinical expert consensus.
CollaborationDeveloped in collaboration with the Agency for Clinical Innovation (ACI) Emergency Care Institute members and the ACI's Surgical Services Taskforce. 
Currency Due for review: July 2027.
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