immunoassay fecal occult blood test

(IH-myoo-noh-A-say FEE-kul uh-KULT ...) iFOBT. A test to check for blood in the stool. A brush is used to collect water drops from around the surface of a stool while it is still in the toilet bowl. The samples are then sent to a laboratory, where they are checked for a human blood protein. Blood in the stool may be a sign of colorectal cancer. Also called iFOBT, immunochemical fecal occult blood test, and immunologic fecal occult blood test.