Guaiac faecal occult blood screening in individuals younger than 50 years of age.

To determine the effectiveness of guaiac faecal occult blood tests (gFOBT) in the early detection of colorectal cancer (CRC) within a population of asymptomatic individuals who attended general periodic examinations, and to suggest the recommended age for this screening tool, the electronic database of the periodic examination institute of Rambam Healthcare Campus for the years 2004-2013 was reviewed. Individuals with positive gFOBT results were interviewed for further workup. Proportions of individuals for whom a polyp or CRC was detected were evaluated according to sex and age.