Anyone ever use a colon cleanse or parasite cleanse?

Can anyone give advise on parasites that people can get? Have you ever used one of those colon cleanses that are either advertised on t.v. or sold in health and vitamin stores? Would you advise being tested for parasites by a doctor and then using a medication or are the herbal remedies just as effective? I have had a lot of strange but subtle health issues lately and the doctor can find nothing wrong with me. I am just wondering if there is anything to this colon cleansing stuff and if it is worth doing.