Wards G4 and F3 at West Suffolk Hospital are currently closed to new admissions after patients showed symptoms of norovirus.
The Bury St Edmunds hospital took the proactive decision to close G4 on Christmas Day after seven patients showed symptoms of the highly contagious diarrhoea and vomiting virus.
That number had reduced to three by yesterday.
F3 closed yesterday after a total of five patients showed norovirus symptoms.
Portable sinks, which makes it easier for visitors to clean their hands with soap and water, have been stationed outside both wards for use when people arrive and leave.
Nichole Day, executive chief nurse at West Suffolk Hospital, said: “Norovirus is very infectious and every year there are cases in the community which transfer to the hospital. Because the virus has an incubation period of several days, people are often unaware that they are carrying it until after they have passed it on.
“We would advise anyone who has had diarrhoea or vomiting to stay away from the hospital for at least 72 hours after they have recovered, even if they feel better.
Otherwise they run the risk of unknowingly passing the highly contagious illness on to someone who is already sick.
“Anyone who visits the hospital should be vigilant and take care to clean their hands. If they are visiting the affected wards, they should use the portable sinks to wash their hands with soap and water when they arrive and before they leave as the alcohol gel is not effective against this virus.”