If you've just tapered off prednisone, then I'm assuming you had a flare-up and things are only quite recently under control. In my opinion, I'd continue on the pentasa enema - as recommended by your doctor. But, if and when you want to get off the pentasa enema you should probably taper off it gradually instead of stopping immediately.
Rio, 32 yr old male - diagnosed with UC in 07/2006.
Alternative therapies for several months (SCD, ayurvedic treatment, VSL#3): didn't work and became anaemic. Canasa, 2 daily: remission for a month then flared-up.
07/07-11/07: 4800mg Asacol (6 x 400mg, twice a day) & Aloe Elite.
Completed first (6 week) tapered course of Pred in 10/07, flaring up since coming off it.
11/07: Switched from Asacol to 12 x 750mg Colazal (3 weeks on it and symptoms got worse)
12/07: Asacol 4800 mg, Started Azathioprine 175mg, Prednisone taper from 60mg - Now on 10mg; 2/08: added 2 Pentasa x 1mg on alternate days.