Yea it's seriously bad stuff, before I decided to have srs/grs I wanted to know what I had decided to get myself into, mind you it didn't matter what the cost or possible consequences I had decided I was ready no matter what, and what I came across was well educational. As most know typically urine is for the most part sterile, that is until it leaves the bladder, at which has point it starts harboring bacteria, and we'll that can go very South very quickly. You can pretty much imagine what could happen if said bacteria filled urine could possibly do if it so happened to make its way to the vagina and got trapped there. In fact this problem does not just effect the trans community alone but also natal born as well. I believe it's called urethral prolapse, another thing I want to mention is it is also important to urinate after Intercourse, to avoid a possible bladder infection. (I had this happen to me, and I didn't know till a girl at work educated me)
Please everyone, I know it's been mentioned but I stress you to follow your Dr's dilation regimen and for those waiting or deciding when or if srs will happen, take what I have said seriously, or the best outcome from the wrong choice could you being a eunuch and peeing in to a bag.