I also did not test positive for the biopsy or the Prometheus test. The Prometheus test showed UC and not sure what the biopsy showed, just not Crohn's. But, I am dx as Crohn's. Have had fissure, skin tags, fistula, all in the lg intestine with both constant ulceration and spotty ulceration. I also could not take AZA, 6-MP, Asacol, Remicade. Humira, mtx don't help. Steroids too often, but at least they help when I'm on them. (Poor bones) Best wishes to you...