When I was there the formal sick pay policy was just the bare legal minimum with some discretion in the hands of HR. If you were sick for just one day and didn't get a doctors note, you never knew if your pay packet would be light at the end of the month.
So people had paid sick days, some unpaid sick days. There was no real policy. I never really manged to figure out how they decided who should have paid and who should have unpaid sick days.
Sick days are highly frowned upon