Cleansing has been around since the time of the Egyptians in 1500 BC. In 500 BC, Hippocrates, often referred to as the "Father of Medicine", suggested using enemas for fever therapy.
The benefits of a cleanse are based on the theory of autointoxication. This is the belief that food not absorbed in the upper intestinal tract passes into the colon where bacterial digestion or fermentation occurs (this part of the theiry is true - see my article on the microbiome https://adoctorsrx.blogspot.com.au/2017/06/the-microbome-and-your-health.html ).
But the theory then goes on to postulate the formation of “poisons” which are absorbed into the bloodstream and are a major factor in the development of a variety of chronic disease states.
Cleansing increased in popularity in the early 1900’s until a medical paper in 1919 discounted the theory of autointoxication. When it became clear that the scientific rationale was erroneous, and colonic irrigation was not merely useless but potentially dangerous, the practice was condemned by the American Medical Association as quackery. The practice of cleansing then went into a decline until its resurrection by alternative health providers in the 1990s.
We now know that the multiple bacteria inhabiting the colon, the microbiome, do indeed metabolize unabsorbed carbohydrates, but instead of being poisons, these short chain fatty acids are necessary for our health. They can reduce the inflammation that aggravates arthritis, lower cholesterol, and may prevent certain cancers. This knowledge would suggest that colon cleansers or laxatives would reduce the absorption of these beneficial nutrients.
In 2009, a systematic review of the worldwide medical literature found “no methodologically rigorous controlled trials of colonic cleansing support the practice for general health promotion.” Yet this practice continues to be recommended by alternative medicine providers.
There are two approaches to cleansing - by mouth and by rectum (colonic enemas or lavage). Both may use large volumes of water (up to 16 gallons for a “colonic”). And the solutions often contain other substances such as herbs or coffee.
These procedures are not risk free. Large volumes of fluid, even if just salt water, can lead to major shifts in the body’s water balance (especially risky if you have kidney or heart problems), and the herbal supplements are not without their potential side effects (imagine how you’d feel if you suddenly drank the caffeine equivalent of 3 or 4 Starbuck’s Grande coffees).
And finally there is the risk of actual physical injury from the enema paraphernalia leading to an intestinal infection or even a perforation of the bowel.
Colon irrigation is
unproven as far as benefits while it has a real risk of adverse
The devices that
practitioners use for the procedure are not approved for colon
cleansing by the US Food and Drug Administration. Inadequately
disinfected or sterilized irrigation machines have been linked to
practitioners are not licensed by a scientifically based
organization. Rather, practitioners have undergone a training
process structured by an organization that is attempting to
institute its own certification and licensing requirements.
If you feel you are carrying around a colon burdened by bad bacteria and toxins, a safer approach might be an increase in daily fiber (flax is easy) and perhaps a probiotic yogurt to shift the bacterial population.