I haven't but recently watched a very interesting documentary on Amazon called "The Science of Fasting". I have been more interested in it since. Seems promising for some diseases, under proper supervision.
Yes it is very interesting indeed...
I have tried it for 7 days back in 2014. I tried it for arthritis but it didnt seem to help, or maybe simply a little, but nothing convincing from what I remember.
Havent tried it for CD.