Besides doing colon hydrotherapy, the other way to do bowel cleansing is by taking supportive herbs and fibers that help to loosen fecal matter, promote peristalsis, and kill off parasites so that the bowel begins to function more efficiently. It is important to drink plenty of water during this time (or any time actually) because without enough water moving through the bowel toxins will be reabsorbed through the colon wall into the bloodstream and fecal matter will become hard.
Herbal formulas usually contain ground flax seeds, psyllium husk, slippery elm, marshmallow root, peppermint, papaya, fennel, grapefruit seed extract, licorice root and other herbs. Most companies have their own proprietary blends containing these herbs and others.
There are several products that I can recommend to you. One is a product called Colonix which can be purchased on-line at http://www.drnatura.com. This website has a wealth of information about the colon and it would be great to check out even if you decide not to purchase the product. Another product is Renew Life Organic Bowel Cleanse. I have seen this product at stores like Sprouts and Wild Oats, however you can get it at a significantly lower price on-line through a website called vitacost. The link to the product is http://www.vitacost.com/RenewLifeOrganicBowelCleanse. Both products are 30-day programs which can be continued for longer if necessary.