How it works
The fecal immunochemical test (FIT), also called an immunochemical fecal occult blood test (iFOBT), is a stool test that also detects occult (hidden) blood in the stool. It is also known as a hemmocult test.
Detecting blood in the stool is important because it can be a sign of precancerous polyps or colorectal cancer. Blood vessels on the surface of larger polyps or cancers are often fragile and may be damaged by passing stool. The damaged blood vessels usually release a small amount of blood into the stool. This blood is often not visible to the naked eye, which is why these tests are helpful.
Does screening really prevent cancer?