[Haematologic disorders in Crohn's disease (author's transl)].

Anemia is the most commonly haematologic disorder observed in Crohn's disease. Secondary megaloblastic anemia related to a nutritional deficiency of vitamin B 12 and/or folic acid is a rare condition as well as auto-immune haemolytic anemia. Iron lack microcytic hypochromic anemia is far more frequent. It is probably due to several causes as microscopic or macroscopic haemorrhages, inflammatory syndrome, disturbance of iron absorption. Hyperleucocytis, hypereosinophilia, hypoprothrombinemia related to the inflammatory syndrome and/or lesions of the bowels are frequently observed in such patients. Anyhow, heamatologic disorders seem markedly correlated with the activity of the disease and should be useful in the follow up patients with Crohn's disease.