I don´t know the answer and I also had a hysterectomy and prior to that I had no problem expelling feces. It seems like I lack water to expel and I resort to something that most medical professionals probably frown upon and that is I use a small enema type bottle and I place only about 3 ounces of water in it and inject it and then it expels the feces. I drink quite a bit of water about 2 liters per day so I am not what you call dehydrated, but I urinate a lot and I think perhaps that is what dehydrates me. I drink no coffee and tryin to minimize diuretics, but yet I still have this problem. I feel handicap because I do this. Sometimes I don´t have to add this water, but usually every other day I do. Trying to find a way to increase the liquid in my stools.
Kaprice, you may want to talk to your doc about having a test that will take a look at how the muscles in your pelvis and rectal area are working. It's a defecogram. It may be able to give you a hand on figuring out what's going on.