While cost‐effectiveness was not an endpoint of this study, a recently published cohort study of patients with gastrointestinal disease and IDA suggested a potential advantage of iv over oral iron in terms of healthcare utilisation due to lower risk of hospital re‐attendance and shorter length of stay.48 Our study showing rapid correction of both anaemia and iron deficiency among FCM‐treated patients with Hb levels <10 g/dL can support the identification of a feasible cut‐off when to prefer iv over oral iron in patients with gastrointestinal disease. This evidence concerns the gene GSTM1 and Iron deficiency anemia.