What Causes Bad Cramps And Bloating Stomach After Having Sex?

Sometimes after haveing sex i get realy bad craps and stomach bloating it sometimes last 2-5 houres and then after the pains gos away my in sides kinda fell a little sore faintly oh yeah ihave notice this has been happenig for about 10 years but will only act up 1-3 times a year and some years their will be no pain

can you tell me what can be my problem