The lesion looks like a large necrotic (dead tissue) ulcer. I assume this was biopsied. I would get a copy of the biopsy report. Necrotic lesions in GI tract can be caused by small blood clots or vasculitis (inflammation of blood vessels). There are blood tests for both. You should have a hypercoagulation panel or at least anticardiolipin antibodies and an ANCA blood test. I would bet your biopsy result would have some clues. Unfortunately you might have to be the main investigator until you get to the proper Dr and diagnosis.