GSTM1 and Iron deficiency anemia: This study also demonstrated that in patients with IBD and either iron-restricted anemia or iron deficiency, FCM administered immediately after IFX in a single session was able to correct both functional iron deficiency as well as true iron deficiency in the majority of patients, as reflected by increases in Hb, hematocrit, s-ferritin and TSAT, markers which are recommended by the ECCO guidelines to show resolution of anemia and normalization of iron stores [6].