Colorectal cancer is a major public health burden worldwide. There is clear-cut evidence that screening will reduce colorectal cancer mortality and the only contentious issue is which screening tool to use. Mos evidence points towards screening with fecal occul blood testing. The immunochemical fecal occult blood tests have a higher sensitivity than the guaiac-based tests. In addition, their automation and haemoglobin quantification allows a threshold for colonoscopy to be selected that can be accommodated within individua health care systems. There is clear-cut evidence that screening will reduce colorectal cancer mortality and the only contentious issue is which screening tool to use.. Mos evidence points towards screening with fecal occul blood testing. The immunochemical fecal occult blood tests have a higher sensitivity than the guaiac-based tests. In addition, their automation and hemoglobin quantification allows a threshold for colonoscopy to be selected that can be accommodated within individua health care systems.