I didn't do a water fast, but I had been on a pretty strict paleo autoimmune diet with very little starch/sugar.

I did flush out the colon with a colonoscopy prep. The 2nd time, I just fasted for 3 days...drinking just water and juice.

Still having colon issues, but I'm still off the prednisone after two weeks. I'll report back soon on how I'm doing!