Sydney's Concord Hospital has closed three wards after 10 patients came down with vomiting and diarrhoea in a suspected outbreak of norovirus.

Three wards have been closed at Concord Hospital in Sydney's inner-west after a gastro outbreak. Credit:Louie Douvis

A spokeswoman for Sydney Local Health District said the wards "have been closed to further admissions as a precaution after 10 patients became symptomatic with vomiting and diarrhoea".

"The patients have been relocated to single rooms and are undergoing testing for

norovirus."

Up to two patients initially presented with gastroenteritis symptoms on Sunday night and were isolated, testing positive for norovirus, the spokeswoman said.