One of the biggest advantages that many companies who make Colon cleansers like to advertise is the fact that the product helps control harmful bacteria and parasites in the colon and intestines. However, the best colon cleanser will destroy these harmful agents while not killing off the intestinal flora in the process. Therefore, try to find a Colon Cleanse product that only uses natural antibiotics as they will not harm the flora but will reduce bacteria and parasite levels and thus help improve overall health.