Tikotiko me ruaki Diarrhoea and vomiting in adults (gastroenteritis)

Gastroenteritis is a term used to describe the combination of diarrhoea, nausea (with or without vomiting), stomach pain and fever. Gastroenteritis is usually caused by an infection in the stomach and intestines.

Causes of gastroenteritis

Gastroenteritis can be caused by viruses such as rotavirus and norovirus, and germ (bacteria) such as:

  • Campylobacter
  • E. coli
  • Salmonella.

You can catch the infection from a person who has it, or by eating food or water containing the germ.

Symptoms of gastroenteritis

Gastroenteritis symptoms include diarrhoea that comes on suddenly and can be bloody. Symptoms can also include:

  • stomach pain or cramp
  • feeling sick (with or without vomiting)
  • a high temperature (fever)
  • muscle aches.

Gastroenteritis usually goes away in a few days, but symptoms can sometimes last from 7 to 10 days, and occasionally even longer.

Diagnosing gastroenteritis

Most cases of gastroenteritis will go away within a few days and do not need any tests. Your healthcare provider may arrange for a sample of your faeces (poo) to be tested if:

  • you have travelled recently
  • your symptoms are particularly severe (such as bleeding, high fever or pain)
  • your symptoms have lasted for a week or more
  • there has been a recent local outbreak of a particular infection.

If the tests find certain types of infection, they may need to report this to the local public health team. They may contact you for more information. This is to help stop the infection spreading further.

Self care with gastroenteritis

Most people do not need to see a healthcare provider and it is best to avoid going to avoid spreading the infection. If you are concerned, call your Healthline for advice on 0800 611 116

The main risk is dehydration and there are a few things you can do to avoid this.

  • Aim to drink plenty of fluid after each episode of diarrhoea. This is on top of your normal fluid intake.
  • If you vomit, wait for 5 to 10 minutes to start drinking then take one sip of water every two to three minutes.
  • Drink mostly water. Avoid drinks with a lot of sugar (such as cola or fruit juice) as this can make diarrhoea worse. You may choose to buy oral rehydration fluids from a pharmacy.
  • Eat as normally as possible but avoid rich or high fat foods.

Paracetamol can help with fever and stomach pain.

Your gut does not absorb some medications (such as epilepsy medication and contraception) as well when you have diarrhoea. Ask your healthcare provider or pharmacist for advice about this if you are not sure what to do.

Getting help with gastroenteritis

You have a higher risk of becoming dehydrated if you have severe, prolonged diarrhoea or vomiting and cannot drink enough fluid. People most at risk of dehydration are:

  • older and frail people or people who have a weakened immune system
  • pregnant people
  • young tamariki (children).

You should go to see your healthcare provider if:

  • you are in one of the groups above most at risk of dehydration
  • you are vomiting a lot and cannot keep fluids down
  • you have blood in your diarrhoea or vomit
  • you have severe stomach pain
  • your symptoms are severe and getting worse
  • your symptoms are not going away after 3 or 4 days
  • you have recently travelled abroad.

If you need to visit your healthcare provider, always tell them about your symptoms in advance. This is so they can put measures in place to stop other people being infected.

Avoid spreading gastroenteritis

To reduce the risk of spreading the infection, it is important to have good hand hygiene. This includes washing you hands with soap and water.

Try to avoid preparing food if you have gastroenteritis. If you do prepare food, make sure you wash and dry your hands well first.

Stay away from work, community gatherings and school or preschool until you or your child have been free of symptoms for 24 to 48 hours. This includes the last time you had diarrhoea.

Stay away from work or school for at least 48 hours after your symptoms have gone away if you:

  • prepare or handle food
  • work in a healthcare or early childhood facility
  • have contact with potentially vulnerable people.

You should wait for at least 2 weeks after the last episode of diarrhoea before you go swimming in a pool.

Preventing gastroenteritis

The best ways to avoid getting gastroenteritis are to practise good hand hygiene and follow food safety advice.

Related websites


Demonstration of how to wash your hands thoroughly.

Ministry of Primary Industries

Guidelines including how to handle raw meat safely and avoid cross-contamination.

Clinical review

This content was written by HealthInfo clinical advisers. It has been adapted for Health Information and Services.

Clinical advisers — HealthInfo (external link)

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