Colorectal cancer is the second most common cause of cancer in the United States. The overall mortality rate approaches 60%. However, the detection of early lesions results in a mortality rate of 20% or less. Therefore, if improvement in survival is to occur, increased efforts need to be focused not only on primary prevention but also on early detection of malignant lesions and the eradication of potentially malignant lesions. There is no universal consensus as to how this can be accomplished. The purpose of this article is to serve as a guideline, providing a practical basis for improving early detection and management of colorectal cancer and its precursors.