Radiographic and colonoscopic correlation in 139 patients with 234 colonic polyps compared the sensitivity of single- and double-contrast barium enema. Single-contrast barium enema detected 68 (80%) of polyps, with 72% of polyps under 1 cm and 94% of those 1 cm or over detected. Double-contrast barium enema detected 135 (91%) of 149 polyps, with 88% of polyps under 1 cm and 96% of larger polyps detected. Thus, the double-contrast barium enema was more effective than the single-contrast examination only for detection of polyps under 1 cm. The single-contrast barium enema was more likely performed on patients in poor physical condition and in those over 70 years old. The results suggest that for elderly patients, who may have difficulty in cooperating for a double-contrast enema, a properly performed single-contrast examination is an acceptable option.