Colorectal cancer (CRC) is the third most common cancer and the third leading cause of cancer death in both men and women in the U.S., with nearly 50,000 deaths each year. Since CRC develops over a number of years from precursor lesions called polyps, it is largely detectable and preventable in early stages. As these polyps become larger, they, like most CRCs, tend to bleed, which is the rationale for the use of fecal occult blood tests (FOBTs) to detect both polyps and cancers early, while they are curable. However, early screening and detection is much less common than it could be, with about 43% of eligible individuals unscreened. Fecal immunochemical tests (FITs) are a type of FOBT that can be a sensitive, specific, and low cost alternative to colonoscopy for CRC screening. Modeling studies have shown that for population screening, a strategy of annual FIT testing from age of 50 to 75 years results in an equal number of life-years gained as compared with colonoscopy every 10 years. However, about 90% of screening in the U.S. is done with colonoscopy, the most expensive and invasive screening test. FITs are far less costly and largely replacing the guaiac test in CRC screening programs internationally, where only individuals with positive results are referred for a colonoscopy. Studies done on FITs in other countries often used FITs not available in the U.S. or studied high-risk populations; thus, results are not applicable in the U.S. It is critical to determine the FIT(s) with the best test characteristics in order to implement successful FIT-based screening programs in this country.