It might sound a severe option, but the pred really does seem to work very well and very quickly for the majority of people - if you're stuck in a flare and the stuff you're on isn't doing the job, it's a fairly sure bet to beat that inflammation into submission. Proctofoam is a steroid in itself anyway (Hydrocortisone), but if you're flaring it may not be staying in (pardon the bluntness) long enough to do its job properly, and so another type of rectal med might not be the answer. Whenever I take a high dose of pred to get back into shape, i'm usually feeling better within a couple of days, and i've been very lucky compared to most in that i don't get a lot of side effects. Hopefully, neither will you!
The important thing is to get yourself into remission and feeling well again, or at least well enough for any other meds to have time to take effect. I also agree with Silent Lucidity about 6MP/Azathioprine, it is excellent stuff if you're having difficulties with steroids (I'm being weaned off the steroids with the help of 6MP).
The important thing to remember is that there are still lots of options, medication-wise, and there is a good chance they'll find the balance that settles your system down.
Hope you're feeling better soon.
Male 30 Years Old.
Diagnosed Pancolitis June 2007
Currently 15mg Prednisolone, 9 tablets Asacol,
50mg Imuran (started Dec 07), 50mg Mercaptopurine (following allergic reaction to Imuran)