Colonic cleansing for radiographic detection of neoplasia: efficacy of the magnesium citrate-castor oil-cleansing enema regimen.

To optimize detection of colonic polyps, we instituted a cleansing regimen of dietary restriction, hydration, magnesium citrate, castor oil, and a cleansing enema. We then conducted a review of serially performed barium enemas to determine the percentage of patients with clean colons in a mixed population of 500 inpatients and outpatients in whom this regimen had been used. The same regimen also was used before single- and double-contrast barium enemas were performed in 139 patients with 234 polyps, and radiologic-endoscopic correlation was used to determine the percentage of polypoid neoplasms detected. The review indicated that a clean colon had been achieved in 97% of the 500 cases. In an additional 1.4% of patients, fecal residue was limited to small amounts in the cecum or ascending colon. In only two cases (0.4%) did fecal material prevent an examination that was suitable for detection of large polypoid or circumferential lesions. The single- and double-contrast barium enemas detected 80% and 91%, respectively, of polypoid lesions of all sizes. Single-contrast examinations detected 94% of polyps 10 mm or larger and 72% of polyps 5-9 mm. Double-contrast studies detected 96% of polyps 10 mm or larger and 88% of those 5-9 mm. The results of this study indicate that with this regimen, fecal residue does not significantly interfere with the detection of colonic polyps via barium enema examination.