I eliminated UC by doing a extended distilled water fast [10+days] 3 times. It returned because I didn't change my diet. Guessing it's been about 5 years since last. It is caused by something you are consuming that your immune system can't tolerate.
By not eating anything, and flushing with the water, you eliminate the cause
BTW, this isn't any protocol that I know of, I just reasoned that if the immune system was involved and was irritated by what I was consuming that fasting would help.