Background and Aims:We analyzed iron deficiency and the therapeutic response following intravenous ferric carboxymaltose in a large single-center inflammatory bowel disease (IBD) cohort. Methods: 250 IBD patients were retrospectively analyzed for iron deficiency and iron deficiency anemia. A subgroup was analyzed regarding efficacy and side effects of iron supplementation with ferric carboxymaltose. Results: In the cohort (n = 250), 54.4% of the patients had serum iron levels <= 60 mu g/dl, 81.2% had ferritin <= 100 ng/ml, and 25.6% had hemoglobin (Hb) of <= 12 g/dl (females) or <= 13 g/dl (males). In the treatment subcohort (n = 80), 83.1% of the patients had iron <= 60% mu g/dl, 90.4% had ferritin <= 100 ng/ml, and 66.7% had Hb <= 12/13 g/dl before ferric carboxymaltose treatment. After a median dose of 500 mg ferric carboxymaltose, 74.7% of the patients reached iron >60 mu g/dl, 61.6% had ferritin >100 ng/ml, and 90.7% reached Hb >12/13 g/dl at follow-up (p < 0.0001 for all parameters vs. pretreatment values). The most frequent adverse event was a transient increase of liver enzymes with male gender as risk factor (p = 0.008, OR 8.62, 95% CI 1.74-41.66). Conclusions: Iron deficiency and anemia are frequent in IBD patients. Treatment with ferric carboxymaltose is efficious, safe and well tolerated in iron-deficient IBD patients. Copyright (C) 2011 S. Karger AG, Basel