Scar tissue from the vasectomy can be considered.
I would also rule out infections, such as STDs. The prostate can be evaluated as well for inflammation or infection. A digital rectal exam or transrectal ultrasound can be considered.
If infection and prostate disease has been ruled out, anatomical abnormalities like a urethral stricture or urethral polyp can be evaluated via a cystoscopy.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
kevinmd_