While colon hydrotherapy may not be the cure for all colon problems, proponents agree that it does seem promising as an effective, natural way to promote well-being and help prevent future health issues. Colon Hydrotherapy QUICK FACTS * Colonics cost between $65 and $90 per session. * Some insurance companies do cover colon hydrotherapy. * "Open systems" require a much smaller tube to be inserted. They are more private, and do not require the constant presence of a hydrotherapist. * "Closed systems" are 100 percent supervised by a hydrotherapist.