[New criteria for detecting occult hemorrhage in screening for colorectal cancer]

The author describes new varieties of fecal occult blood screening strategies in respect to old and up-to-date diagnostic methods. The limited sensitivity and specificity of the classical methods used for the demonstration of occult fecal blood necessitate the introduction of new techniques in the screening practice. The new discoveries in molecular biology are likely to improve the effectiveness of the early detection of colorectal cancers and their precursor lesions. Since the implementation of these novel techniques in mass screenings has not taken place yet, higher effectiveness can only be achieved by more specific and sensitive blood tests.