An enema is a procedure that involves inserting a liquid into the rectum to induce bowel evacuation. There are several types of enemas that are used for different purposes. Cleansing enemas are most commonly used to remove feces from the bowel when a person is constipated. They work by irritating the intestinal lining and distending the colon to stimulate bowel movement. Retention enemas are used to introduce medications or oils into the lower bowel and are meant to be retained for longer periods of time. Precautions must be taken when giving an enema to avoid potential complications like fluid overload, electrolyte imbalances, or trauma to the rectal tissues.