Colorectal carcinoma (CRC) is the third most common cause of cancer diagnosed in the United States, and the second leading cause of cancer death. Although rates of the disease have been going down in recent years, results can be further improved. About 90% of people whose cancer colon is caught before it has spread to nearby lymph nodes or organs survive more than 5 years after diagnosis. However, only 10% of patients whose cancer has spread to distant parts of the body survive 5 years. Diagnosis at an early stage aims to reduce the incidence of tumors in an advanced stage and hence mortality. Nevertheless, the two corner stones for the diagnosis of established colorectal cancer are the clinical picture and the investigations.