On forums such as this, you will find people who have problems of various kinds after surgery -- the ones who have no problems tend not to post here!
If JJ is in good shape, that will help the operation to go more smoothly. Of course many things might go wrong -- but that doesn't mean they will go wrong! The large majority of surgeries are uneventful.
Expect a period of incontinence and ED after treatment -- that is the experience of many in here, although some lucky ones have neither.