I'm sure in my case, POIS has nothing to do with orgasm neither with semen ; It's all about sexual arousal with orgasm being part of it
When I discovered POIS 2 years ago, I could masturbate or have a sexual relation without orgasm and not having any POIS symtoms ;
Today, I orgasm once a week, sometimes less, If I play with sex, i'm in POIS pretty much automaticly ;
Whats have changed ?
I think I limited so much myself that I get sexual aroused and get pleasure much more easily than before ; I'm also kinda premature ejaculator(never had that before) ; In other words by abstaning myself, I can reach pleasure much quicker and easily wich trigger POIS symtoms.
Of course, Orgasm, is what is the most obvious ; its is the absolute pleasure,that make the worst and the longest symtoms but maybe we should not focus only in Orgasm ;
The question is : what happens chemicaly/physicly when we(normal people included) are sexually aroused ?