Blood that is in the faeces or vomitus that is not obvious by general inspection. Used as a diagnostic screening test for colon cancer. Tests for occult blood are generally colourimetric. Stool sample will turn blue when a particular chemical reagent is mixed with the specimen on test paper. Kits for measuring occult blood in the stools are now ava...
that present in such small amounts as to be detectable only by chemical tests or by spectroscopic or microscopic examination.
Type: Term Definitions: 1. blood in the feces in amounts too small to be seen but detectable by chemical tests.
blood in the faeces that can be detected only by chemical tests 
blood in the stool that is not visible to the naked eye.