However, although heme breakdown is less than globin during intestinal transit, false negative results can be seen with the stool guaiac tests due to degradation of the peroxidase-activity.
22.
The guaienes are sesquiterpenes with the molecular formula C 15 H 24 . ?-Guaiene is the most common and was first isolated from guaiac wood oil from " Bulnesia sarmientoi ".
23.
From its wood, also, a type of oil known as oil of guaiac ( or " guayacol " ) is produced, to be used as an ingredient for soaps and perfumes.
24.
The stool guaiac test for hidden ( occult ) blood in the stool can be done at home or in the doctor's office, or can be performed on samples submitted to a clinical laboratory.
25.
The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30 %, but if a standard three tests are done as recommended the sensitivity rises to 92 %.
26.
Conversely, 800 mg of cimetidine 1 hr before the start and again at 50 miles of a 100-mile running race substantially decreased GI symptoms and postrace guaiac test positivity but did not affect race performance.
27.
All three recommendation panels recommended replacing any older low-sensitivity, guaiac-based fecal occult blood testing ( gFOBT ) with either newer high-sensitivity guaiac-based fecal occult blood testing ( hs gFOBT ) or fecal immunochemical testing ( FIT ).
28.
All three recommendation panels recommended replacing any older low-sensitivity, guaiac-based fecal occult blood testing ( gFOBT ) with either newer high-sensitivity guaiac-based fecal occult blood testing ( hs gFOBT ) or fecal immunochemical testing ( FIT ).
29.
The test involves placing a faecal 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.
30.
Several recent colon cancer screening guidelines have recommended replacing any older low-sensitivity, guaiac-based fecal occult blood testing ( gFOBT ) with either newer high-sensitivity guaiac-based fecal occult blood testing ( gFOBT ) or fecal immunochemical testing ( FIT ), which tests for globin rather than the heme detected by the guaiac method.
