How do I sync my iphone 5s to my outlook calendars.? .

It seemed to work recently but now it has stopped syncing. The calendar on the iphone 5 is different to the Outlook calendar I use at work. My IT person said its not possible to sync Outlook with Iphone 5s . Is that right ? If so how do I use my work calendar and get it onto my phone with out deleting everything. help driivng me mad.