i am a 61-year old male. i have not had sexual intercourse for about 2 years. however, during the last 2 years i have found that when i masterbate it is followed by 3 or 4 days of passing blood and sometimes clots of blood in my urine. when it first occurred i thought that i might have kidney stones and did not associate the passing of blood with masterbation but now i see that the two are linked. needless to say, i do not indulge in masterbation now but i would like to know the cause of these symptoms. please treat this question seriously as i am worried about my health. thank you in anticipation.