INFLUENCE OF IRON PREPARATIONS ON OCCULT BLOOD TESTS.

Ferrous fumarate (Fersamal) and ferrous carbonate (Ferrodic) may produce false-positive results with the orthotolidine tablet tests (Occultest and Hematest) if administered to patients being investigated for alimentary bleeding. Misleading results are also likely if the benzidine test is employed as a filter-paper procedure. Ferrous sulphate, gluconate, succinate, iron and ammonium citrate, and other preparations of iron have no influence on the modern tablet tests for occult alimentary bleeding.