I am 35 year old and if I ejaculate more than once a day either from
sexual intercourse or masterbation, I feel a kind of symptom like
prostatitis.

For example, a kind of burning feeling comes from the prostate area,
and I feel like that I want to pee or go to stool.  And sometimes (not
always), there is a burning urinating feeling.

I went to see my doctor 3 months ago when this happened, he checked my
prostate from my anaus and said that my prostate did not seem to have
inflammation.

I also had urine sample test, STD test, both of them came out normal.

Again, the kind of symptom I mentioned above only happens if I
ejaculate more than once within 24 hours.  I am not promiscuous at all
and I have only one sex partner.

And the symptom go away itself the next day.

What do you people think this might be?  Should I go see a urinologist?