It varies. If you buy a bowel cleaning program, they usually last about 30 days.
The liquid Bentonite and psyllium husk--there is no set time frame for that. Most people stay on it until they see results. But, be careful because some people have developed problems taking it. It can back you up and cause serious pain. You have to drink your water with it!
I have done several different kinds of colon cleansings and gotten different results everytime.