WOW! Thanks for all the great replies.
Some of the medicenes I have tried, other than prednisone, are Asacol, Mesalamine, Imuran, and Remicade. Unfortnately, none of these medicenes are effective. Also, because of the PSC I am limited on what medicenes I can take. Actually, I had to be taken off Imuran before it even had time to work, because it adversely affected my liver.
As for the PSC, no one really knows a lot about it, especially me. What I understand so far is that it is similar to UC, in that it is an autoimmune disease. The difference is that it affects the bile ducts of the liver. While the bile ducts are inflamed, the bile backs up into the liver causing liver damage. There's no treatment for it currently, and eventually transplantation will probably be necessary. People with both PSC and UC are at a higher risk for colon cancer, so that's another reason why the Dr.s think it might be a good idea to take it out.