An enema is an enema, also known as a colonic irrigation. An enema is an enema catheter that is inserted through the anus, about 20cm into the colon and then filled with an enema solution such as warm water, warm saline or glycerin, or a medicinal solution. The purpose of the enema is to promote fecal elimination, clean the intestinal tract, and also to instill medication to treat intestinal disorders. 1. Promote fecal discharge: enema can soften feces, stimulate intestinal peristalsis, so as to achieve the treatment of constipation, discharge of persistent feces, intestinal toxin removal and other purposes. 2. Clean the intestinal tract: part of the anorectal part of the surgery, due to surgical operation needs, in the preoperative need for enema, so that the surgical part of the clean, so as to do a better operation, such as colorectal tumors, hemorrhoids surgery and so on. 3. Therapeutic effect: enema can be added to the corresponding drugs for the treatment of certain diseases, such as ulcerative colitis patients can use salicylic acid drugs enema treatment; pediatric fever patients can use enema to reduce fever and so on. Enema also has some hazards, such as damage to the perianal and rectal, can cause perianal edema or inflammation and other conditions. Enemas should be used with caution in pregnant women, and women should not take enemas during menstruation.