I'm having stomach problems?

It started last december when i started having really bad stomach pains, and i spent three days in the hospital because my mri showed that i had i inflamed intestines. then i started feeling it starting up again back in may and spent the night in the hospital as a "precaution" and then had a colonoscopy in june that found benign polyps in my colon. now im starting to feel pains again, and im having diarrhea sometimes and charcoal black stool. aside from going to the doctor/hospital again, is there any advice or insight as to what this might be?