What Causes Pain In Rectum After Surgery To Repair Prolapsed Rectum?

I had surgery in september to repair a prolapsed rectum and a prolapsed bladder. I continue to have pain in the rectal area, which the surgeon calls "rectal spasms." He prescribed valium suppositories, which help but which put me to sleep. Is this a normal condition? If so, for how long? Other treatments? He has told me not to do Kegels while this continues, but how else to strenghten pelvic floor?