The National Party is demanding an independent investigation into the norovirus outbreak at Dunedin Hospital last week.
More than 160 staff and patients at Dunedin and Waikari hospitals became sick with the stomach bug which closed wards and caused the postponement of 2300 outpatient appointments.
National's health spokesman, Tony Ryall, says now that the hospital is back to normal an independent investigation is needed to make sure such outbreaks can be better managed in future.
The hospital says it will be doing its own internal debrief but is open to a wider inquiry.
However, it says it may never know exactly how the outbreak was caused.
Dunedin Hospital is rebooking all patients whose appointments were cancelled after all services there and at Wakari Hospital resumed on Monday.