Colorectal cancer (CRC) is the second common cause of death in the Western world, and is very increasing in Japan. Fecal occult blood test (FOBT) is used routinely for CRC screening, which has been shown to reduce the incidence, morbidity, and mortality of CRC. However, there is a need to develop a novel method to improve sensitivity. The investigators reported that Fecal COX-2 assay, one of fecal RNA test, is potentially useful for colorectal cancer screening (Gastroenterology 127; 422-427, 2004). So the investigators planed to compare fecal RNA test with FOBT for detecting colorectal cancer and adenoma.