Colorectal cancer screening in individuals at average risk is effective, although the screening test considered the best remains uncertain. Randomized studies of fecal occult blood testing (conducted in the 1990s) and one-time screening sigmoidoscopy (conducted in the 2000s) demonstrated that patients who were screened had colorectal cancer detected at an earlier stage, resulting in reduction of colorectal cancer incidence and mortality. Virtually all health care organizations and many governments now endorse colorectal cancer screening.
Lieberman D. Colorectal Cancer Screening With Colonoscopy. JAMA Intern Med. 2016;176(7):903-904. doi:10.1001/jamainternmed.2016.1333