Colonic irrigation is the process of flushing large amounts of water into the intestinal tract, reaching the upper portions of the bowel.

Enemas have legitimate uses but can be abused. Allegedly, colonics and enemas "detoxify" the system, taking out internal poisons so that diseases can be cured. They are often recommended in unproven therapies for cancer and by alternative practitioners for a variety of unrelated illnesses.

Colonic irrigation owes much to Max Gerson, a German physician who died...