The British Society of Gastroenterology has revised its guidelines for the management of iron deficiency anemia in adults. Published in the journal Gut, the updated guidelines have made several recommendations relating to definition of anemia, clinical assessment, treatment, monitoring and special situations such as anemia in young women, comorbidities, anemia following gastrointestinal surgery among others.

According to the guideline, hemoglobin below the lower limit of the normal reference range as defined by the laboratory conducting the test is defined as anemia. A good marker of iron deficiency anemia is serum ferritin, although transferrin saturation can come in handy if results of ferritin are doubtful. Increase in hemoglobin by ≥10 g/L within two weeks in anaemic patients is highly suggestive of absolute iron deficiency.

A carefully elicited history provides useful clues to clinical decision making. This guideline too has emphasized on detailed history taking as a guide to managing the individual patient.

Besides iron studies to confirm the diagnosis, other tests that can be done are urinalysis or urine microscopy,  screening for celiac disease including upper and lower GI endoscopy as indicated. The guideline does not recommend fecal immunochemical testing for now due to inadequate evidence supporting its utility. Gastroscopy and colonoscopy are advised as the preferred GI investigations in men and postmenopausal women with newly diagnosed iron deficiency anemia. CT colonography can be done in those who are not suitable candidates for colonoscopy. Capsule endoscopy (preferred method) or CT/MR enterography (alternative method) to evaluate the small intestine for any inflammatory and neoplastic lesion. If capsule endoscopy yields no positive findings, investigate further if the anemia persists despite iron replacement.

Iron replacement therapy should be started with ferrous sulphate, fumarate or gluconate tablets (one tablet per day). The dose can be reduced to every alternate day or parenteral iron can be considered in case of intolerance to oral iron. However, treatment should not be delayed for want of test results unless colonoscopy is imminent. If oral iron supplementation is ineffective or contraindicated, parenteral iron supplementation should be considered. Monitor patients for response to oral iron in the first four weeks of therapy and continue supplementation for around 3 months after hemoglobin levels become normal. Periodic complete blood counts, every 6 months, are recommended to detect recurrence of iron deficiency. Patients with inflammatory bowel disease particularly are candidates for parenteral iron as they are more likely to develop intolerance to oral iron. Iron malabsorption is also common in them.

Premenopausal women should undergo serology to screen for celiac disease. Endoscopic evaluation in this age group is indicated if there is family history of colorectal cancer, persistent iron deficiency anemia, age over 50 years and presence of red flag symptoms such as rectal bleeding, anorexia and/or loss of weight.

Iron deficiency is common in conditions like chronic kidney disease, chronic heart failure, bariatric surgery. However, other causes of iron deficiency anemia should be investigated even if there is a history of GI or bariatric surgery in new presentations of iron deficiency anemia.

Reference

1. Snook J, et al. British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults. Gut. 2021 Sep 8:gutjnl-2021-325210.