What is the difference between a ct colonoscopy and a barium enema?

CT colonoscopy: is a CT scan with specific technical parameters. There is a bowel prep to clear out the colon, and a tube is placed into the rectum to fill the colon with air. A barium enema uses x-ray/fluoroscopy instead of CT. With a rectal tube, the colon is filled with barium and air, and the patient placed in different positions for viewing. Barium enema has been largely replaced by colonoscopy.