My biopsies were negative for the same, just have inflammation. I am suspected to have Crohn's but all diagnostic testing was inconclusive and frankly it's a complete waste of your time because whether it's Crohn's, pouchitis or "new IBD variant", it's going to have to be treated and all treatments for these disorders on people like us are exactly the same. Your Doc's diagnosis is probably correct but it doesn't matter because it's likely not going to change anything as far as treatment. My doctors stopped wasting time with diagnostic testing for the same reasons a long time ago.
I had the Prometheus blood test. Total waste of time. It was read by two pathologists - at Mount Sinai and one on the west coast - as inconclusive. Even if it was conclusive it wouldn't matter. So it's a waste of your time IMHO.