Updated 25 July 2018

FAQs about gastroenteritis

A registered dietitian answers seven frequently asked questions about gastroenteritis.

1. Are gastro and flu the same illness?
No, gastro (often known as stomach flu) and flu are not the same thing. Gastro is an infection caused by a variety of viruses, such as rotaviruses and noroviruses, but it isn’t caused by influenza viruses.  

Flu affects the respiratory system (nose, throat, lungs etc.) and symptoms include coughing, congestion, fever and muscle aches. Gastro, on the other hand, affects the intestines with the principal symptoms being diarrhoea, vomiting and stomach ache.  

2. How long am I contagious if I have gastro?
A number of different viruses can cause gastro, and the contagious period is slightly different for each virus. Generally, you can be contagious from a few days up to two weeks or more. 

With norovirus, which is the most common cause of viral gastro, you’re contagious from the time you start to feel ill until about three days after you’ve recovered, and some people stay contagious up to two weeks after they’ve recovered.

3. What are the symptoms of gastroenteritis?
The most common symptoms of gastroenteritis are diarrhoea, vomiting and abdominal pain.  Symptoms such as fever, headache, chills and muscle aches can also occur.

Symptoms appear 24 to 48 hours after the infection and generally last 12 to 60 hours.

4. What treatments are available for gastroenteritis?
There’s no specific treatment for viral gastroenteritis.

However, it’s important to ensure that you don’t become dehydrated by drinking liquids, such as water with a little salt and sugar (oral rehydration solutions can be bought or made at home), ‘sports’ drinks, juice and/or soup.

5. How long does gastroenteritis last in a child?
Gastroenteritis in children can last anywhere from just a day or two to around 10 days. The time period depends on the type of virus as well as how strong the child’s immune system is.

Children tend to vomit for the first day or two, but the diarrhoea can last more than a week.

6. Can gastroenteritis be prevented?
It’s almost impossible to completely avoid contact with the viral and bacterial causes, and therefore almost everyone can suffer from gastroenteritis a few times in their life.

However, there are ways to prevent gastroenteritis. The most important is strict hygiene (i.e. proper hand washing) as well as cooking food thoroughly. 

7. Is it a good idea to follow the BRAT diet if I have gastroenteritis?
The BRAT diet includes bananas, rice, applesauce and toast. This diet was once recommended as a treatment for diarrhoea. However, the BRAT diet is very low in nutrition, especially protein and fat.

It’s fine to eat these foods only for the first day or so, but you should start incorporating more foods to increase your nutrition as soon as you can.  

Reviewed by Kim Hofmann, registered dietitian, BSc Medical (Honours) Nutrition and Dietetics, BSc (Honours) Psychology. December 2017.