Do azo pills take away a urinary track infection or does it just relieve the pain?

I think I have a bladder infection because it burns when I pee and there was more blood then normal. I got cranberry juice and azo pills, I have been taking them as well as drinking alot of water. It feels alot better but I was wondering if the azo pills will take the infection away completly or if I should go to the doctor within a couple days if it hasn't gone away??