2 doctors weighed in:

Fecal occult blood test and other signs of GI bleeding reliable?

2 doctors weighed in
Dr. Gurmukh Singh
Pathology
1 doctor agrees

In brief: Not specific

Fecal occult blood tests detects peroxide activity in the fecal matter. Peroxidase activity is associated with hemoglobin, but not specific to it.
Horse radish, among other things, has peroxidase activity, as does blood in meats. Fobt may be positive for any bleed from gums to hemorrhoids but is not specific for any diagnosis. It is a screening test, which if positive, needs more tests.

In brief: Not specific

Fecal occult blood tests detects peroxide activity in the fecal matter. Peroxidase activity is associated with hemoglobin, but not specific to it.
Horse radish, among other things, has peroxidase activity, as does blood in meats. Fobt may be positive for any bleed from gums to hemorrhoids but is not specific for any diagnosis. It is a screening test, which if positive, needs more tests.
Dr. Gurmukh Singh
Dr. Gurmukh Singh
Thank
1 comment
Dr. Lester Thompson
Many vegetables (cruciferous specifically) give a positive result -- which is why your diet should be altered before doing the test. Hemorrhoids are a common "false positive."
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