What is the optimal treatment for anemia in inflammatory bowel disease?

Anemia is common in inflammatory bowel disease (IBD), with a prevalence ranging from 8.8% to 73.7%. This wide range reflects the definitions used and the populations studied. Although many patients are reported to be asymptomatic, systematic studies have shown anemia to have a significant impact on quality of life. Consequently treatment should be instituted early. The commonest cause of anemia in IBD is iron deficiency, predominantly related to gastrointestinal blood loss. Anemia of chronic disease often occurs concomitantly, due to cytokine-mediated impaired erythropoiesis and dysregulated iron metabolism. Oral iron is a simple and effective method for treating iron deficiency, but requires long courses of treatment. It is also theoretically implicated with worsening intestinal inflammation, via the production of toxic reactive oxygen species. Intravenous iron avoids these concerns, especially with the development of ferric carboxymaltose, which allow up to 1000mg to be given rapidly. In patients failing to respond to intravenous iron, the anemia of chronic disease is most likely to be causative. In this setting evidence suggests that additional erythropoietin therapy can be effective. Blood transfusions should be avoided as part of routine management and reserved for patients with substantial acute gastro-intestinal bleeding, where there is a risk of hemodynamic compromise. This article discusses the underlying physiology of anemia in IBD, and presents the current evidence supporting treatment options available.