Anemia is a frequent extraenteric complication of
inflammatory bowel disease (IBD,
Crohn's disease and
ulcerative colitis). A systematic review of the literature shows that the overall prevalence of
anemia ranges from 8.8% to 73.7% but differs whether in a setting of
Crohn's disease or
ulcerative colitis. A disabling complication of IBD,
anemia worsens the patient's general condition and quality of life, and increases hospitalization rates. Different factors, including
vitamin B12 and
folic acid deficiency, bone marrow suppression secondary to
drug therapy,
autoimmune hemolytic anemia and the coexistence of
myelodysplastic syndromes are involved in the pathogenesis of
anemia in IBD. The main types of
anemia in IBD are
iron deficiency anemia and
anemia accompanying
chronic diseases. Correct diagnostic definition of
anemia is a fundamental step in guiding the choice of therapeutic options, since the co-presence of different pathogenetic factors may sometimes require a more complex treatment plan. A review of
anemia in IBD, its pathogenetic features, epidemiology, diagnosis and
therapy based on evidence from recent studies is the focus of this article.