I Have Blood In My Ejaculate But Not In My

I have blood in my ejaculate but not in my urine. An urologist took an instrument and inserted it into my penis. I am 50 years old and after this procedure I became partially impotent. Before this my sex life was excellent. I was told later that the procedure used was wrong and that I was just suffering from a virus which would eventually go away. Why would an urologist insert an instrument into the penis if the problem was not in the outlet but was where the semen originates?