Sorry I got the giggles thinking ... hmmm. When we don't use parts of our bodies, no matter which ones, and then it gets a workout I guess it does make sense when it becomes sore. If it continues though, I would do a check in with your doctor.
I guess that's one of the good things about not having that area. Mine was SO sore before ... fistulas, abscesses, and 'roids, that I put up with the 6 month healing time compared to the ten years of extreme discomfort.
.... and the pickles are spicy! Something I couldn't eat before surgery. Kinda would STING!
Crohn's Disease, Colostomy due to cancer and I make darned good dill pickles.