No change at all. You probably had whatever you had all along and nothing "developed." The treatments are exactly the same for Crohn's and Pouchitis so the labels are irrelevant - completely and totally. You need to not focus on arbitrary labels, and instead focus on treatment. It's inflammation and whether you call it UC, Crohn's or pouchitis, it's bowel Inflammation and bowel inflammation needs to be treated. And the treatments are in most cases the same, and the game is "let's find what works for YOU". Remicade is used for UC, Crohn's and Pouchitis. So what you call it makes no difference at all except to pathologists and maybe in some cases to insurers. In my case they have waffled between a diagnosis of Pouchitis and Crohn's for 15 years. A ton of money was spent on diagnostic tests, and none of them was ever conclusive. We don't even know that your biopsy is conclusive, it's just one pathologist's opinion. My biopsies were looked at by top pathologists on East and West Coast and they were uncertain.
There is treatable Crohn's and untreatable pouchitis. In those cases they are using or trying the same meds or groups of meds. You try to find something that works and labels have nothing to do with that inquiry, at all. What you call the inflammation has nothing to do with whether the medication will work. So what you need to do is find a treatment that works and not worry about diagnosis. Do worry about untreated inflammation because that is all that it is without a label.