eric, I am sorry that you're having so much trouble with c. diff. Supposably people with Colitis are much more prone to getting infected with c diff than the general population, just another fun side effect of having colitis. Are you taking vancomyacin? Were you diagnosed by colonoscopy or by stool samples? I thought I had c. diff last time I had a scope but luckily it came back negative. I have seen a lot of members dealing with c. diff in the past and even a few with recurrent c. diff infections. I hope some of them respond with useful tips on erradicating the bacteria.
Try to think positive, things will get better.
You could also do a search for fecal transplant or speak with your GI about it. They won't use the procedure for colitis but I believe it is approved for treatment of c. diff. If you do it on your own, you have ot be very careful about testing the donor for illness.