Ok you may think this is a bit of a strange thing to be ranting about, but it really need a new one ripped.
In short, colonics just take tomorrows shit out today. LITERALLY.
Colonics supposedly remove 'toxins' from your body. The first problem we have here is that there is no such thing as 'toxins' if you ask a Colonic Hydrotherapist or whatever they want to be called, they will not be able to name a single toxin, because they don't exist. Furthermore, these imaginary 'toxins' supposedly sit in the "pockets of the colon" (which conveniently do not exist either) and poison your body.
The idea that your body poisoned itself through its colon was generally accepted around the early 1900's, but was proved wrong in 1919 by Alvarez WC and again in 1922 by Donaldson AN after scientific testing showed otherwise.
If you're interested in reading more on colonics Click Here.