Testing for Crohn's

I have been unwell for almost 2 years now, for the first year i got told it was IBS and given tablets that later put me in hospital. I have constant diarrhea, stomach pain, bloating to the point i have very bad strech marks now,tiredness, pain in my joints and inflammation of the eyes.

I have had blood test and a flexi-scope. Bloods were fine but they found what looked like inflammation but when they checked the biopcy it was normal. Does anyone have an idea what could that be?
I have also had an MRI of the small bowel and came back fine so they discharged me (Grr hate it when they give up on you when there is something wrong but they cant be bothered) but it is only my large bowel that is causing problems, my last consultant said Crohn's now they dont know.