Stool guaiac test

Stool guaiac test
Guaiac cards and bottle of developer that contains hydrogen peroxide
MedlinePlus003393
HCPCS-L2G0394
Both square test 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 test is performed.

The stool guaiac test or guaiac fecal occult blood test (gFOBT) is one of several methods that detects the presence of fecal occult blood[1] (blood invisible in the feces).[2] The test involves placing a fecal sample on guaiac paper (containing a phenolic compound, alpha-guaiaconic acid, extracted from the wood resin of Guaiacum 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 testing as a colorectal cancer screening tool, in favor of the fecal immunochemical test (FIT).[3] Though the FIT is preferred, even the guaiac FOB testing of average risk populations may have been sufficient to reduce the mortality associated with colon cancer by about 25%.[4] With this lower efficacy, it was not always cost effective to screen a large population with gFOBT.[5][6][7][8]

  1. ^ "Guidance for Industry and FDA Staff — Review Criteria for Assessment of Qualitative Fecal Occult Blood In Vitro Diagnostic Devices". United States Food and Drug Administration Office of In Vitro Diagnostic Device Evaluation and Safety. August 8, 2007.
  2. ^ "Fecal occult blood". www.fda.gov. Retrieved October 26, 2010.
  3. ^ Rex DK, Johnson, DA, Anderson, JC, Schoenfeld, PS, Burke, CA, Inadomi, JM, American College of, Gastroenterology (Mar 2009). "American College of Gastroenterology guidelines for colorectal cancer screening 2009 [corrected]". The American Journal of Gastroenterology. 104 (3): 739–50. doi:10.1038/ajg.2009.104. PMID 19240699. S2CID 295873.
  4. ^ Bretthauer M (August 2010). "Evidence for colorectal cancer screening". Best Pract Res Clin Anaesthesiol. 24 (4): 417–25. doi:10.1016/j.bpg.2010.06.005. PMID 20833346.
  5. ^ Mandel JS, Bond JH, Church TR, et al. (1993). "Reducing mortality from colorectal cancer by screening for fecal occult blood". N Engl J Med. 328 (19): 1365–71. doi:10.1056/nejm199305133281901. PMID 8474513.
  6. ^ Hardcastle JD, Chamberlain JO, Robinson MH, et al. (1996). "Randomised controlled trial of fecal occult blood screening for colorectal cancer". Lancet. 348 (9040): 1472–77. doi:10.1016/s0140-6736(96)03386-7. PMID 8942775. S2CID 11395104.
  7. ^ Kronborg O, Fenger C, Olsen J, et al. (1996). "Randomised study of screening for colorectal cancer with fecal occult blood test". Lancet. 348 (9040): 1467–71. doi:10.1016/s0140-6736(96)03430-7. PMID 8942774. S2CID 37515050.
  8. ^ Kewenter J, Brevinge H, Engaras B, et al. (1994). "Results of screening, rescreening and follow up in a prospective randomized study for detection of colorectal cancer by fecal occult-blood testing: results of 68,308 subjects". Scand J Gastroenterol. 29 (5): 468–73. doi:10.3109/00365529409096840. PMID 8036464.