Colon preparation for the barium enema: a guide for the radiologist

Double-contrast barium enema technique

During a double-contrast barium enema the radiologist interacts with the patient, the controls of the fluoroscope, and the image on the television monitor. The radiologist paints an image of the colon; the barium is the paint, the colon is the canvas. The radiologist manipulates the barium pool, the air column, and the patient to create images. Although the radiologist may have a plan going into the examination, the game plan is altered by the patient's ability to tolerate and perform the study, the length of the colon, and pathology encountered. If the radiologist understands the goals to be achieved, the studied can be tailored to fit what is happening in the fluoroscopic suite.

Double-contrast barium enema examination technique

This review article presents the principles for performing a safe, comfortable, and accurate double-contrast barium enema examination. The procedure is a flexible examination in which the fluoroscopist interacts with the patient, the controls of the fluoroscope, and the image on the television monitor. During a double-contrast examination, images of the colon are created by manipulating the patient, the barium pool, and the amount of air insufflated into the rectum. Fluoroscopy is essential for guiding the radiologist to obtain spot images with adequate technical factors. The fluoroscopist analyzes the luminal contour, the barium-coated mucosal surface en face, and the barium pool to detect abnormalities in the colon. With careful technique, a high-quality examination can be performed in most patients.

Dietary fibers in the preparation of the bowel for diagnostic barium enema

The effect on colon cleanness of adding dietary fiber or placebo to a standard bowel preparation scheme before diagnostic barium enemas was tested in a randomized, double-blind study including 120 consecutive outpatients admitted for diagnostic barium enemas. Colon cleanness was scored as satisfactory, intermediate, or unsatisfactory. No case of unsatisfactory cleansing appeared in the group given fiber. Mean score was slightly better in the fiber group but the difference was not statistically significant. Dietary fiber does not have a negative effect on colon cleansing but may instead have a beneficial effect, which is possibly more pronounced in patients with constipation.

Predictive value of a diagnosis of colonic polyp on the double-contrast barium enema

The positive predictive value of a diagnosis of colonic polyp on the double-contrast barium enema was determined by analyzing 160 polypoid lesions reported in 105 patients. Of the 160 polyps, 139 were confirmed by endoscopy, surgery, or repeat barium enema for a positive predictive value of 87%. Twenty-one lesions were not confirmed despite repeat endoscopy, repeat barium enema, review of the original study, or surgery, giving a false positive rate of 13%. The individual false positive error rates of 5 radiologists ranged from 8% to 26%. False positive errors were due to stool, diverticula, air bubbles, misinterpretation of the ileocecal valve, and haustration. Many of the false positive errors appeared to have been avoidable if the original examination had been more meticulously interpreted.