Thanks for your query.Based on the facts that you have posted it appears that you have undergone Radical
4 years back and has symptoms of UTI with slight bleeding at the end of the urination .
This is mostly due to cystitis
and can be cured wit antibiotics that your family Physician has prescribed you.
However it is better to consult your Urologist
for evaluation and as a routine follow up after Prostatectomy.