Hi Carla,
I did extensive research before I decided to dish out the dough on a colon cleansing product.  Colonix by Dr Natura had the best reviews out of all.  They suggest that you do it for at least 2 months to start.  You can actually purchase the products on ebay for less and get them quicker.  I suggest you check out the forum under Colonix.  My recent and on-going success story is posted.  Also, check out the Dr Natura website - the pics on there will gross you out and amaze you.  http://www.drnatura.com/colonix_program.php

hope this helps!

Good luck