I posted a question about Pred earlier and there is alot of good information from people who have experience with it. It is entitled "I have a stupid question about Pred"
I was on 40 mgs of Pred for two weeks and noticed a slight improvement. My symptoms weren't all that severe to begin with, however. I had some blood and no diarrhea.
Anyway, I would say call your doc. If it concerns you, it should concern him/her.
Like I said, there is some really good information in my previous post.
40 mgs of Pred
50 mgs of Imuran
1 Canasa at night