There are claims that a lot of the plant based ingredient in colon cleansers are really toxic for the body and can cause damage to your body if you use them.  I agree that along with everything else you put in your body you need to know what it is, and do your research.  Especially without FDA monitoring most of this stuff.  There is a big risk for problems and side effects.  Plus make sure you read the labels. 

If it says not to use it more than a few times a year, don’t.  Some people think that doing a weekly or monthly colon cleanse might be fine, and it might depending on the products you use.  With some you are just stripping out everything from your colon and leaving the inside irritated.  This doesn’t help with vitamin or mineral absorption either.  Sometimes less is more.  Or too much of a good thing can be bad. Also make sure that you know what the ingredients are.  If you are buying from a health food store, they know their stuff, but they are also there to make money.  So do the research on your own before you take anything?  And if you have any adverse reactions, call your doctor.