I came across this explanation on the MDA forum. I was wondering if maybe we should make this a sticky for the newbies who periodically come asking about cleanses and detoxes?
"The whole idea of "cleansing" and "detox" for your bowels comes from a flawed idea of how digestion works. A lot of people think that waste can "build up" in your colon, or that mysterious "toxins" can accumulate there, and that you need to "flush" the system out.
What actually happens, unless you have diverticulitis, is that your gut lining is continually shedding itself and the tissues are regularly renewed, just like your skin and every other tissue that comes in contact with foreign substances. Normal people without serious bowel diseases do not store up any waste, toxic or otherwise, in their bowels.
What these "cleanses" and "flushes" do is give you diarrhea, which comes with all sorts of risks including dehydration and hyponatremia. Diarrhea is a natural response to disease agents and poisons in your lower GI tract, but it's costly and not something you should induce without good reason. And if you have a good reason, your body will make it happen.
The other thing that happens is you seriously deplete your healthy gut flora, which take time to recolonize, and that leaves a big hole in your immune response as well as upsetting your digestion until that can happen. It leaves the door open for C. diff, yeasts and other nasties to move in and exploit resources that they normally wouldn't be able to compete for effectively, making you sick.
Bottom line, inducing diarrhea without a damn good reason is useless at best, and dangerous at worst."