We report the case of a 43-years-old Turkish man with acquired deficiency of factor V (FV) diagnosed in a usual screening before a (recto) colonoscopy. In the biologic explorations, activated partial prothrombin time (APTT) was abnormally high and prothrombin time (PT) was low 18IU/dL with no anticoagulant drugs (the PT was normal 6 months ago). The controlled level of factor V was 3IU/dL with FV antibodies (9 Bethesda Units/mL). This patient had a previous history of primary sclerosing cholangitis (2000) and ulcero haemorrhagic rectocolitis (2002) and a fortuitous biological Biermer's disease was revealed. Corticosteroids were prescribed at 1mg/kg/day with decreasing during 6 months, patient had gradual regression of the caused bleeding and FV became greater than 90%, F V antibodies decreased to less than 0.7 Bethesda Units/mL. This case illustrates the presence of FV inhibitor in an autoimmune gastrointestinal context with regression of clinical (caused) signs and antibodies with corticosteroids.