Hey Shortstuff! Welcome! :)
I say skip the pred for now. I would definitely ask for the 5asa enemas - Rowasa etc. And then I would use those at night and the Cortenemas in the morning. The combo should definitely kick some UC butt!
Where exactly is your UC located? Perhaps a different 5asa drug will work better for you. I have left sided and I take Colazal because it has been shown to release later in the colon than some of the others - getting to the affected area better.
Have you tried probiotics?