Ulcerative Colitis

I have just recieved my positive result all biopsys where negative but my dr kept doing blood work. Finally some lab out in California said I had it. I guess it was an antibody test. The colon examine showed a inflamed large intestine . Now he wants me to start on a 40mg prednisone course thats 8 pills a day for two weeks  Then 7 pills a day for two weeks and on and on then if my problem isnt under control I go on it for 2 years straight . Does anyone know how bad this is going to be I know I have A good chance for MOON FACE which I dont want I am really worried about all the side effect associated with this drug please help if possible .Any replies would be great