Prednisolone (which is the same thing as prednisone) does wonders for getting a flare under control for most people. For myself, I only take it as a last resort because of the side-effects, but not everyone has the same reactions to pred. If you've never taken it before, give it a try, but educate yourself about what it is doing first. Do some research online, and be sure to read all the literature that comes with the prescrip.
If your colitis is mainly in the lower part of your intestine, you might try a rectal med with hydrocortisone, or even a pred enema. You get the benefit of the pred without the nasty side-effects. They generally only help colitis lower down, so if you have colitis going up the left side, or extends more than 10 to 15 cms, rectal meds might not reach far enough to help.
I have taken pred before and successfully tapered off. I was then off it for a year, and my symptoms didn't return until I stopped taking Asacol and a full on flare started. Pred is a wonder drug for me...it gives me a stomache of steel, where I can eat whatever I want with no problems, and my symptoms go away within a few days. The side-effects I don't like are the insomnia, faster hair growth, back-ne, increased appetite, and mood swings. That is a pretty daunting list I admit, but those effects are more manageable than constant D, bleeding, and getting cramps from gas.
I think most people will say they have benefitted from pred, but they didn't tolerate the side-effects well. You have to weigh the advantages of getting your UC under control against the possible bad stuff from pred. I hope this helps you. If it were me, I'd give rectal meds a try, maybe add in a probiotic, before taking the pred, but don't discount it all together. If your flare is interfering with your life a great deal, pred might be the thing that helps you regain control.