You´re very welcome. How long is your fast going to last?
My advice, Watermelon sounds good, but eat small portions every 2 hours. Combine with 100% juice of some kind, you can buy them made (Pomegranate is great by POM) or make them yourself with a juicer (It wasen´t worth it for me to buy a juicer to use it for 4 days, granted juice is better quality when fresh so if you can afford it buy it).
I don´t know about the fiber, I have never taken fiber in my life. Even fasting I allowed the body to work on it´s own, no enemas or things like that. My mistake was mostly refeeding, and I had read the warnings but didn´t take them seriously. Well...please do!