You need more fiber in your diet. I buy big containers of generic Metamucil at WalMart and take a teaspoon or two before each meal. Don't take any before your post-lifting shake, but you just need to get more fiber in. Start with lower doses, because if you start out with a lot, you will bloat and get gut aches.
Something tells me you just started taking protein. If thats the case, take half the dose cos your system isn't ready to digest all of it, and that results in bad gas. Plus I see above your young and like half my weight. What I was tring to say is take half the dose at a time, don't exceed 50g in an hour or its over for your ass. Consider your metabolism too, as you lift more and stuff your body can handle more. Hope this helps.