The OnSite FOB Rapid Test is an immunochemical test device intended for the qualitative detection of fecal occult blood to be used in laboratories or physician offices. It is a useful aid to detect bleeding caused by a number of gastrointestinal disorders, e.g., diverticulitis, colitis, polyps, and colorectal cancer. Fecal occult blood tests are recommended for use in 1) routine physical examinations, 2) routine hospital testing, 3) screening for colorectal cancer or gastrointestinal bleeding from any source.