St. Paul's Hospital in Saskatoon was hit Friday with an outbreak resembling the Norwalk virus. (CBC)

Two units remain closed to visitors at St. Paul's Hospital in Saskatoon, following an outbreak of Norwalk-like illness just prior to the weekend.

The first cases were noticed on Friday.

On Monday officials said 23 patients and five staff members have fallen sick.

They added that if no new cases were noted, it might be possible to reopen the affected units to visitors as soon as Wednesday.

Even though doctors are treating the outbreak like they would the Norwalk virus, Morrison said the hospital will be able to confirm if it is a Norwalk outbreak on Monday.

Officials have said that during an outbreak, any staff that has worked on the infected unit wouldn't be able to work on any other unit for 48 hours after being on that ward.

Symptoms include diarrhea and vomiting, and people are typically sick for two to three days.