I Had A Radical Prostatectomy 2 Years Ago, Recently Had

I had a radical prostatectomy 2 years ago, recently had what felt like kidney stones , then while driving cross country in New Mexico at 7500' passed a couple large brown pieces of soft tissue and some blood through my urethra....seems like I remember the radiologist saying this could happen as a result of the radiation, a "snuffing" off of the bladder lining due to burning of the bladder during treatments....true?