occult blood test [L, occultare, to hide; AS, blod + L, testum, crucible] , a test for the presence of microscopic amounts of blood in the feces secondary to bleeding in the digestive tract. The fecal immunochemical test (FIT) is a newer kind of stool test to detect hidden blood in the stool. It is more specific than other kinds of occult blood tests as it identifies only human blood and does not require special dietary preparation. Kinds include gFOBT, guaiac test.
