Every few nights for perhaps a good 30 seconds and then possibly more than
once in an hour then nothing for a few nights, I get this intense pain in
the prostate. I mean so intense I cant walk, battle not to fall to my knees
howling on the spot and you name it in the pelvic region, the pain goes
there. Never seems to radiate beyond my stomach in an upwards direction but
it's front, back, left and right but always starts in the prostate region
and within seconds is everywhere.

After that 30 seconds or so, it is gone like someone turned a light switch
off. I thought "sh.t coming" at first or "fart coming" too but no, neither
of those events came nor did they have anything to do with it because sh.t 
or fart, I am OK and even when a little constipated I am OK, no real pain to
speak of (well SOME pain but I wont whinge about it).

So I have been suspecting the prostate may be the cause and yes, did get a
flare up again so put it down to that. Got the pain mostly under control but
those bouts of intense pain still happen. I thought maybe it was my diet but
no, it seems to have no correlation with diet at all. Doesn't seem to be
stomach muscles either. My job involves me getting into air ducts, crawling
around and so on and though I am not fit, I am not badly off really and even
at 50 can get up from sitting on the floor like I used to as a kid when I
truly WAS fit.

Thus, I have come to the only conclusion that, without medical experience,
seems open to me (eg, I don't know enough to think of any other medical
reason). Any of you who have had prostate cancer - does this sound in any
way familiar? Thanks for cogent responses.