Anemia is the most common hematologic disorder in patients with ulcer- ative colitis (UC). In some cases, normochromic anemia results from the pres- ence of chronic disease; however blood loss or malabsorption may lead to an iron de ciency anemia with hypochromic appearance. Other rare hematologic manifestations associated with UC include myelodysplastic syndromes and leukemia. Several investigators have suggested a clinical association between in ammatory bowel disease and myelodysplastic syndrome, which may they share an immune dysfunction and impairment of T-lymphocytes activities. UC is an in ammatory bowel disease of unknown etiology that mainly affects the mucosa of the colon. Immune mechanisms play an important role in UC, and immunogenetic
