Intestinal lavage is medically known as enema, divided into retention enema and cleansing enema, which mainly treats intestinal diseases or prepares for gastrointestinal endoscopy. For patients with long-term constipation, ulcerative colitis, and incomplete intestinal obstruction, enemas can remove intestinal lodging, expel toxins and metabolic wastes from the intestine, relieve obstruction, reduce toxin absorption, and mitigate the damage to the body from intestinal toxins. Cleansing the intestine by enema can expose the intestinal mucosa more clearly and help in endoscopy. If disease is detected bacteriological, microbiological and immunological examination of intestinal fluid can be performed to further clarify the diagnosis of the condition. Normal people are not recommended to cleanse the intestine because the intestinal mucosa itself has the ability to regulate, excessive bowel cleansing, which interferes with the function of the intestinal mucosa and breaks the dynamic balance in the intestine, can also stimulate the intestinal peristalsis to increase the speed of inducing abdominal pain.