A barium enema is good way to look for disease and any narrowed areas or large tumors, but it may miss small polyps, cancers, or inflammation. If a problem is found, a colonoscopy may still be required. A perforation or a tear in the lining of the intestine occurs in about one out of every 25,000 barium enemas.
A barium enema takes about 1 to 2 hours. The barium may cause constipation and make your stool turn gray or white for a few days after the procedure.