Bad Stomach Cramps for A Year?

I have had terrible stomach cramps for about a year now. I am a teenage boy and I have been tested for everything the doctors can think of. I have had catscans, mri's, an endoscopy, exploratory stomach surgery, and more. I have gone to blood, cancer, gastro, ID, and allergists. On some of my tests(HIDA for one) the results have been close enough to pointing something out but never outright results. Initially they found out my spleen was enlarged and had an extra part. While the surgeon found this odd and told us he thinks it could be related to my problems, the rest of the doctors brushed it off. He thinks it could be pushing up against my diaphragm and causing pain. I was hoping someone could give me their thoughts. Anything would help; I have been in terrible pain for a year and even tests we have done before would at least be helpful. Thank you.