I've not heard of polyps being common...but see that it can happen in 7 - 50% of people. That's a pretty big range to me,
I would concern myself with them being in the rectum since UC's inflammation does start there...
Are you on any rectal meds?
Did the doc remove them all?
Please make sure you get a copy of the results rather than just hearing the results. You should have it for your records and for your research to know what the exact words mean.
I hope all are clear.
q