I've not tried any long course of pred in the past, but I can definitely relate to your unresponsiveness to meds. Its unbelievably frustrating and very scary. Based on my short (but horrible) experience with this disease, may I suggest that you go full-force with the spinach/sunflower diet? Since you're already doing it anyway, I think you should do it exactly as Cfromutah suggests (he's the one who thought up this diet) and see what happens. When I didn't respond to any meds or diets (including the Specific Carbohydrate Diet), I figured I had nothing to lose and gave the spinach/sunflower diet a shot. For 2 weeks I felt worse, the third week wasn't quite so bad, and after that I started seeing constant improvement with my symptoms. I'm now off ALL meds. Even I can't believe it.
I should also mention that in addition to the spinach diet, I also did a low-residue diet initially since my colon was so raw. Also, only eat cooked spinach - fresh is too rough.
I hope that helps, and I hope you see some improvement soon...
Katie, 30. Chicago 'burbs.
DX: Pancolitis as of 9/08 (Proctitis as of 1/08)
Current Treament: Spinach/sunflower & Low-residue diet.
Previous Treatment: Canasa suppositories, Cortifoam, Prednisone, Colazal, Symex DuoTabs, Rowasa, Bentyl, Cortenema, Asacol, Iron, Zoloft, Acidophilus.
Status: Near total remission