I have infrequent blood (I think) spotting from my penis. It is visible in my underwear. There may be some relation between a strenuous bowel movement or cardio exercise and the spotting. Two recent urine tests have found no blood in the urine. A recent colonoscopy was negative except for a slight hemorrhoid.
I had part of a kidney removed a couple years ago due to kidney cancer. A bladder scan done around the same time was negative.
The spotting has been occurring for the last couple years, perhaps coincidentally when I first began using Viagra. My urologist originally dismissed the bleeding and any connection to the Viagra use. He now wants to do another bladder scan, though I have no symptoms (as I know them) of bladder cancer.