Upset stomach-mom

For the last three weeks my stomach has been hurting off and on. It aches, I feel like vomming, I get gassy, and sometimes a one-time diarrhea the next day. It's so bad that last night I just laid in bed with my baby waiting for it to go away. At first I kept blaming it on random things--oh the Hawaiian food I ate was bad, or I haven't eaten in a while, or I am tired. But the more often I get it, the more confusing it is... Anyone else have GI issues?