What Causes Red Clots With Each Urination After A Hysterectomy?

I have had a hysterectomy 11 years ago, today i am experiencing frequent urination about 2 to 5 min. apart with pressure down below. While only a small amount with pressure and burning, light red blood dripping in toilet with pencil eraser size blood clots with each urination. After i wipe there is light red on the toilet paper and none on my panties. No pain involved. What could this be????