barium enema, a rectal infusion of barium sulfate, a radiopaque contrast medium, which is retained in the lower intestinal tract during radiographic studies for diagnosis of obstruction, tumors, or other abnormalities. It is important to evacuate the barium completely following the study; a mild laxative is usually prescribed for this purpose. The procedure may be used therapeutically in children to reduce nonstrangulated intussusception. Also called contrast enema.
