Both square<unk>  areas in the upper area of the card show the intense blue color of a positive result. The lower two smaller circular areas on the orange stripe are analytical control reactions, positive on the left and negative on the right, that help assure that the card and developer bottle have been maintained in proper conditions and have not been damaged before the<unk>  is performed. The<unk>  or<unk>  fecal occult blood<unk>  (gFOBT) is one of several methods that detects the presence of fecal occult blood (blood invisible in the feces). The<unk>  involves placing a fecal sample on<unk>  paper (containing a phenolic compound, alpha-guaiaconic acid, extracted from the wood resin of<unk> um trees) and applying hydrogen peroxide which, in the presence of blood, yields a blue reaction product within seconds. The American College of Gastroenterology has recommended the abandoning of gFOBT<unk> ing as a colorectal cancer screening tool, in favor of the fecal immunochemical<unk>  (FIT). Though the FIT is preferred, even the<unk>  FOB<unk> ing of average risk populations may have been sufficient to reduce the mortality associated with colon cancer by about 25%. With this lower efficacy, it was not always cost effective to screen a large population with gFOBT.
Stool guaiac test
Fecal fat test
Fecal pH test
Stool test
Fecal occult blood
Rapid urease test
Capsule endoscopy
Double-balloon enteroscopy