Professor Brett Sutton, the state's Chief Health Officer, has urged parents and carers to keep young children at home if they are sick.

Outbreak reports are up fourfold from the five-year average.

Two outbreaks have been recorded in the Bendigo region.

"Viral gastroenteritis is highly infectious," an advice message, issued by Professor Sutton's office, said.

"Symptoms include nausea, vomiting, diarrhoea, fever, abdominal pain, headache and muscle aches, with more severe outcomes in the elderly and very young.

"Symptoms can take up to three days to develop and usually last between one or two days, sometimes longer."

Washing hands with soap and water was one of the most effective ways of preventing the spread of infection, the advice message stated.

Cleaning and sanitising were also important infection control measures.

"Alcohol-based hand sanitisers are not effective against many common viruses that cause gastroenteritis," the message said.

It urged parents and staff at childcare centres to be vigilant for symptoms of gastroenteritis in children and to reinforce basic hygiene measures.

"Infants or children in childcare or school, as well as staff, who develop vomiting or diarrhoea should stay at home until at least 48 hours after their symptoms have stopped, since they will still be infectious," the Chief Health Officer advised.

People recovering from gastroenteritis should also avoid visiting hospitals, childcare centres and aged care facilities to avoid spreading the infection to those most vulnerable.

"Any person living in a household with someone who has gastroenteritis should refrain from visiting these high-risk facilities until at least 48 hours after the last person in the household has recovered," Professor Sutton advised.

He urged anyone concerned or experiencing severe or persistent symptoms to see a GP for advice and possible testing.

For more information about gastroenteritis, visit betterhealth.vic.gov.au/health/conditionsandtreatments/gastroenteritis