Acquired Factor VIII Inhibitor Presenting as Occult GI Bleeding.

An acquired coagulation factor deficiency is characterized by acquired autoantibodies against specific clotting factors in those without diagnosed hemophilia. It is a relatively rare condition with an incidence of approximately one case per million per year. We present a case report of an elderly male who initially presented with an occult GI bleed that was identified with a positive fecal occult blood test result. This is the first case reported to our knowledge of an acquired factor inhibitor deficiency presenting in this manner. We postulate the importance of acquired factor inhibitors in the setting of unexplained anemia given absence of overt clinical symptoms that could contribute to aggravate an established GI bleed, especially in the elderly population.