Stomach problems? What is going on?

Since the beginning of January my stomach has been making really weird growling/rumbling sounds (sometimes it sounds like im farting, but im not!) and I can feel stuff moving around violently all over my stomach. I can even feel pressure under my ribs all the way down to the bottom of my stomach when it growls. I get cramps when it happens too, and it always happens about 1-2 hours after I eat a meal so I know it's not hunger (and I don't feel hungry). What is going on????