An individual receiving an enema draws his knees to his chest and lies on his stomach or side while the administrator inserts a lubricated tube into the rectum and delivers a saline solution through the tube, explains Healthline. The individual normally has a bowel movement within an hour.
An enema cleans the lower bowel, states Healthline. It is the treatment of last resort for constipation if diet, exercise and laxatives are not effective. Patients receiving examinations of the colon, such as a colonoscopy or X-ray of the colon, may undergo an enema prior to the procedure. While enemas are normally safe when properly administered, rectal tissue can become damaged or irritated if the administrator forces the tube into the rectum.