The prednisone should work pretty quick. I didn't get or need as much sleep when I'm on it, the extra energy was the only good thing about it. It also gave me night sweats, like you describe. You'll notice lots of other wierd side effects. It can also have some serious side effect, but I still turn to prednisone to get through flares, and 40 mg is a good strong dose.
You describe stomach cramps, but would you say it is actually spasms in your gut (down lower)? Stomach cramps might be something besides UC
49 year old female attorney, diagnosed UC/pancolitis 1985, no surgery but much suffering.
Asacol/5ASA maintenance for 20+ years, usually 3 pills 2x day.
tapering OFF prednisone from lingering flare;
August 2008 sought care of naturopathic doctor. Tested gluten intolerant and started gluten-free, soy-free, etc. diet which resolved flare. Also Replete probiotic, DGL (licorice root, slippery elm), Permeability Factors. Slow-release iron and B-12 shots for severe anemia.
Sept: Mild case of thrush in throat, prescribed antifungal mouthwash.