This would be best addressed in colonic/enema forum because Valerie is very knowledgeable.
With that said, I have had colonics done and I see the reason is, if I stay in the guidelines she gives me, I have a better release with the colonic then otherwise. Also, the gas can be quite a pressure in your gut and then when it finally releases...ugh...it was all for naught! I have had that a few times, thinking a LOT was moving through me and then very little to none moved.
So the suggestions are for an easier and more efficient colonic.
I have one scheduled for Wednesday this week. I think I will begin tomorrow to just eating salads and see how it differs from the other colonics.