Diagnosed with UC - now they saying it’s not

Hi, I had on and off symptoms to suggest IBD in 2014 - colonoscopy was normal but was fine during this time when they did the scope -I wasn’t having symptoms. I went back with ongoing symptoms and was told I possibly had IBS and bleeding from piles. I was also struggling with fatigue, cramps, weight loss. My symptoms continued . I was finally diagnosed with UC in 2016 (I was pregnant during the flare was hospitalised) they couldn’t do a full colonoscopy at time - but did a part sigmoidoscopy and took biopsy’s and from that they said probable UC. I was treated with steroids and the mesalazine to control the disease. Treatment worked - and bowel problems stopped, pain cramping fatigue all largely under control. Had colonoscopy May 2019 and biopsy and told I was in remission. Felt good

Yesterday I had an appointment with a consultant (a new one - this is my third) - after asking me how I was -symptoms and what medication I was taking. She then told me she didnt think I actually had ulcerative colitis - that None of my tests show any actual classic signs of it - she not sure who decided to run with that diagnosis

She thinks the flare that hospitalised me was infective colitis

She ideally wants to take me off my medication - to see if I get symptoms - then re scope!

She says I might have IBS and not IBD after all

I’m very distressed - she says she won’t take my medication away unless I agree - but that if my symptoms changed she’d not prescribe anything like biological drug without the confirmed diagnosis

Any advice ? I feel like I need to be prepared for when I go back - like I’m in a nightmare