How long have you been bulking?
While stomach cramps happen to everyone sometimes, if its a chronic thing you need to make some adjustments before it causes some damage. Chronic stomach cramps is technically a sign of IBS, but since you've been bulking and don't have a history I doubt thats your problem.
Do you eat enough fiber? Make sure you at least get 30 grams per day (some ppl suggest 40-50). Also, it could be an effect from eating too much of one type of food. If you eat eggs 6 times per day or diary with every meal I'd say to lighten up on it.