[Means of improving the diagnosis of cancer of the large intestine].

Problems of perfecting diagnosis of colorectal cancers are discussed with a view to identification of follow-up groups and improvement in methods for X-ray examination and subsequent diagnostic procedures. Double-contrast enema examination should be preferred in those at high risk for cancer of the large bowel. Follow-up groups were identified on the basis of risk factors. Patients' preparation for double-contrast enema including saline and contact purgatives, residue-free diet and hydration is described. The composition of a high-contrast barium suspension is given. The method of primary double-contrast enema, the required projections and other roentgenologic technicalities, which ensure the diagnostic value of the procedure are discussed. Complex syndrome-based roentgeno-endoscopic examination programs are suggested.