FOB Test

The guaiac Faecal Occult Blood  Test or (gFOBT) was the test used by UK National Bowel Cancer Screening when the service was first set up in 2006.  It is a simple test that has been used for many years to confirm the presence of blood in faeces which, with appropriate symptoms, would indicate the need for further clinical investigations, usually colonoscopy.

gFOBT uses guaiac, a gum harvested from a tropical tree, ‘guaiacum officinale’, which turns blue in the presence of hydrogen peroxide and human or animal blood.

In England the Bowel Cancer Screening programme replaced gFOBT with ‘FIT’ (Faecal Immunochemical Test), which detects only human blood  (not that from meat etc) and detects very small quantities of blood. FIT is much simpler to use because it requires only one small poo sample rather than three which was necessary with gFOBT.