that happens to me too only when i eat spicy food or anything with dairy in it. My poor girfriend has to oput up with the noise and the wrenching smell but her farts are bad too so she cant complain !! all I can say is maybe your diet has something to do with it..
have u been to the doctors might be irritable bowel syndrone IBS
RCHT gave a good answer. I would try some digestive aids and also some activated Charcoal capsules, this will help with the gas and tummy ache.
-could be a reaction to a specific food item, cut it out of your diet and see if the issue remains, then slowing introduce it again-see what happens
-not enough water
-too much fiber and not enough water
-constipation- re: not enough water
-reaction to medication
-new food
-not enough fiber so the food is literally rotting in your system
-eating eggs or other sulfate based food
-eating to fast and ingesting to much air
-not enough exercise so the food is moving to slow in your digestive system: hence off gassing
-indication of underlying medical condition
-beans are hard to digest and will cause gas
-lack of proper balance of intestinal beneficial bacteria