ETYM Latin enema, Greek, to send in; en in + hienai to send.
Injection of a liquid through the anus to stimulate evacuation; sometimes used for diagnostic purposes; SYN. clyster.
Infusion of liquid into the rectum to evacuate fecal obstruction or to introduce drugs for treatment, or radio-opaque material (barium sulfate) in order to define the colon on X-ray. Injection of liquid into rectum.