For the past few weeks, when I ejaculate during masturbation, I feel a mild aching twinge in my left lower abdomen while ejaculating. It doesn't seem to be my prostate; I know where that is, and the pain definitely doesn't originate anywhere near there; the spot is a bit to the left and further up. It is definitely not in my penis or testicles. Just afterwards, if I press there (just below my belly line on left side closer to where my leg meets my abdomen) I can feel a small amount of pain there. It always goes away after about a minute or two. The mild pain starts just as I'm about to climax, so I assume it's because semen is on the move. I have no discomfort during urination. Some relevant history - I had Syphilis 15 years ago (successfully treated) and I've had no other STDs that I'm aware of. I haven't had sex with anyone since about that time, but I do masturbate several times per week. Do you think I might have a cyst or stone in a vesicle or ureter or something like that?

Welcome to the Forum and thanks for your question.  I'll be glad to comment.  From the sound of things, the pain is entirely reproducible.  Is it getting better or worse over time?  Does it occur every time you masturbate of only some of the time? 

These symptoms are certainly not a sign of any STI, not a long term sequelae.  Ejaculation involves muscular contraction and both the description you provide and the location suggest that this might be an event involving either the pelvic musculature or, as you suggest, some sort of localized process.  This sort of difficulty sounds like more of a urological process than something that falls within my expertise.  I would suggest keeping a diary, noting the precise location, timing relative to ejaculation, and whether or not it occurs with every ejaculation or intermittently so that you can completely describe it to a urologist.  Unless it is progressive, I suspect that taking the time to carefully document what is going on will help your urologist to help sort this out.

I hope these suggestions are helpful.  EWH

---