Enema (plural enemata or enemas) or clyster, is a fluid injected into the lower bowel by way of the rectum. The most frequent use of an enema is to relieve constipation or for bowel cleansing before a medical examination or procedure. In standard medicine an enema may also be employed as a lower gastrointestinal series (also called a barium enema), to check diarrhea, as a vehicle for the administration of food, water or medicine, as a stimulant to the general system, as a local application and, more rarely, as a means of reducing temperature, as treatment for encopresis, and as a form of rehydration therapy (proctoclysis) in patients for whom intravenous therapy is not applicable.