It looks to me like you have been tapered off the pred WAY too quickly. From my vast experience of pred, if you start to come down off it while still having symptoms you are virtually guaranteed to flare up again.
I would speak to your GI and suggest staying on 20mg until you have no more blood. Also I think 5mg drops are way too big. I think you should taper by 2.5mg a week until you get to 15mg and then go even slower. (I come down by 1mg).
It is not easy coming off pred but doing it too fast it a recipe for disaster.
Abatacept Trial since Feb 2008 (Maintenance Period)
Back on Pred - 3mg - Steroid Dependent :-(
Actonel 35mg, EPA Fish Oils
Predfoam Enema - Had to stop as not allowed during trial
Asacol x 9, Lialda (Mezavant)
Remicade every 8 weeks (Stopped working)
Aloe Vera Lily of the Desert Juice Gave me the worst D !
Primadophilus Reuteri Probiotic