Absolutely it is possible to have perineal pain for weeks & months after surgery. Remember that those little scars that were entry points for robotic arms that really did a job on your insides. They will heal long before the internals heal completely.
I was having pains of vague origin at 4 months out, and was still having bits of the partially-dissolved internal suture material surface at that point.
I also had three rounds of UTIs, mainly because I was still leaking badly. Wet / damp pads were a big risk of generating new UTIs.
BMs are passing through a rectum that had the prostate cut away from it, so you can certainly have very different sensations there. Remember that your DRE was rectal -
Talk to your Uro / surgeon, as nothing unusual or unexpected should be ignored. On the other hand, it may be simple healing. Stay away from searching the web to find problems you might have - someone somewhere will find a disease for you.