Save yourself a bunch of money and skip the spendy-trendy products. Find a natural food, or health food store and buy some psyllium seed husk. You want the super-fine ground stuff that's like, 10mg/tsp, not the 5mg stuff that's quite common. It's harder to find but works 100x better. It's also cheap. The last I bought was something like $3 for a half pound or something.
There are programs designed to do a thorough colon cleanse. If you want the real skinny on it, go to http://www.hsu.com/internal_cleansing_program.htm
The woman who runs this store is local, and very reputable. She has a long list of clients who have recovered from some serious ailaments as a result of her programs. I used to do roughly 2 cleansings a year, but it's been a while. I should probably do one soon. I usualy do a modified version of her program, one that costs a lot less.
I'm not necessarily recommending her products per se, but there's a lot of useful information on her website.
Good luck...if you stick with it you'll be amazed at how good it'll make you feel.
BTW, regardless of what you decide to do, drink LOTS of good
water, as it will help flush the toxins out of your system, and keep you hydrated. Doing a cleanse like this what often causes people problems is they get dehydrated.
[This message has been edited by Taijiguy (edited 06-14-2006).]