Have you had any other tests run? I think a colonoscopy/endoscopy would be helpful, and some stool tests (fecal lactoferrin antigen and fecal calprotectin). CT enterography would probably be a good diagnostic tool in your case, as well.
This may have been asked before, but have you had any more blood work done? I think a good starting place would be CRP, CBC with differential, complete metabolic panel, sedimentation rate and platelet count. A histone test may be helpful...You may want to get tested for both C. diff and Small Intestine Bacterial Overgrowth (SIBO) as these could be causing your symptoms, as well.