Hawke's Bay Hospital has closed its Acute Assessment Unit (AAU) to act as an isolation unit, as more people have presented in the last 24 hours with a stomach bug.
On Wednesday six people were admitted to hospital and more turned up at the Emergency Department yesterday.
Chief medical officer for the hospital John Gommans said AAU had been closed so people who have vomiting and diarrhoea and need hospital care could be isolated to prevent the bug spreading to other areas of the hospital.
Dr Gommans said stomach bugs spread easily and older and younger people are often more vulnerable to dehydration and needing hospital care.
People should not visit anyone in hospital if they have had a stomach bug in the past 48 hours, as the bug can spread easily through a hospital.