On Friday, the region closed Surgery 5-B and fifth floor medicine to try to contain the outbreak.
Donna Wiens, director of infection prevention and control, says the virus causes vomiting and diarrhea for 24 to 48 hours, but some have it longer.
The last person to get it was reported on Saturday and they have to wait for four days without a case to reopen the two floors to normal operations.
The region hinted the virus is likely Norwalk, but it is still unconfirmed.
Though often associated with food preparation, the region says viruses like Norwalk, which are not airborne, still often spread in hospitals because of close-quarters and shared washrooms.