Iron Deficiency Anaemia and Anaemia of Inflammation in Enteropathies Caused by Commonest Small Intestine Disorders: Current Evidence

It is no mystery that iron deficiency is the most common anaemia and multiple studies have shown that anaemia is a main factor for decreased quality of life. The focus of our article is an up-to-date review of different enteropathies caused by specific disorders and the prevalence of iron deficiency anaemia (IDA), starting with the understanding of physiology of iron absorption and regulation in the intestine. The pathologies that we tried to cover were celiac disease, Crohn’s disease, nonsteroidal anti-inflammatory drugs (NSAID)-induced enteropathy and protein losing enteropathy. Unfortunately, not everything still understood and questions still remain. The main questions are associated with our understanding of iron regulation beyond the ferroportin-hepcidin axis and what mechanism is behind changes of epithelium in different conditions. Depending on the study and pathology of enteropathy, almost half of the studied patients had iron deficiency anaemia. However, in all enteropathies, IDA is more an additional finding or an additional symptom that needs further investigations. That is why many authors consider that IDA is caused by secondary mechanisms and not enteropathy per se and should be correlating with undernourishment, severe mucosal atrophy, malabsorption, and bleeding.