There is a system in the body called the entero-hepatic circulation system, where bile is reabsorbed before it has a chance to be secreted in the stool. You may also recall that cholesterol has to be excreted in this way without being reabsorbed, so an increase in fibre serves both your cleansing as well as your cholesterol needs. It is interesting that one of the most important risk factors for colorectal cancer is sustained constipation. The net effect of constipation, of course, is that everything that was bound for excretion, ends up being exposed to the intestinal wall for a prolonged period of time. Remember that the first half of the liver's job is to render each toxin water-soluble.
Solubility is made easier with a proper hydration level.
The kidneys, as mentioned in the beginning, are also an important organ for detoxification. Botanicals such as equisetum are gentle stimulants for the kidneys. The body uses the skin as a route of excretion as well, so rigorous skin brushing after a shower is also recommended during a cleanse. And to give the digestive tract a break, I encourage a two-week period simplified eating. It should be noted that starting a formal cleanse should be done under the supervision of a qualified physician.