I appreciate that you bring this up. I believe in rhis very same thread, hundreds of pages ago someone had asked a similar question and I brought up the fact that the pelvic floor musculature and anchor points of said muscles and ligaments are very different between men and women.
During srs, a stinkditch is litterly bored right through pelvic floor muscles and into the body cavity. The muscle is torn apart to make room for the now void space. Specifically, the lower part of the bulbospongiosus and transverse perineal muscles are cut into and opened.
This is a major problem, because if you compare these two sets of muscles to female anatomy, you can see that they are much smaller than a females.
This causes the body to loose a massive amount of structural integrity especially in things as mundane as walking correctly and pain free. Since everything is so weakened, the body naturally tries all it can to tighten the remaining muscle tissue to compensate for the lack of strength. Weak muscles always get tight.
Now look at a female pelvic floor diagram. The transverse perineal muscles are easily 3 to 4 times larger than a males, and anchor strongly to the hips, hammocking around the natural opening of the vaginal canal. This difference is what alows a woman to comfortably walk and move about and still allows ample space for the vagina.