Iron Deficiency Anemia Guidelines

Updated: Aug 23, 2023
  • Author: James L Harper, MD; Chief Editor: Emmanuel C Besa, MD  more...
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Guidelines Summary

Guidelines from the American Gastroenterological Association on the evaluation of iron deficiency anemia include the following recommendations [45] :

  • In patients with anemia, a cutoff of 45 ng/mL is recommended over 15 ng/mL when using ferritin to diagnose iron deficiency.
  • In asymptomatic postmenopausal women and men with iron deficiency anemia, bidirectional endoscopy is recommended over no endoscopy.
  • In asymptomatic premenopausal women with iron deficiency anemia, bidirectional endoscopy is suggested over iron replacement therapy only.
  • In patients with iron deficiency anemia without other identifiable etiology after bidirectional endoscopy, noninvasive testing for  Helicobacter pylori, followed by treatment if positive, is suggested over no testing.
  • In patients with iron deficiency anemia, suggest against routine gastric biopsies to diagnose atrophic gastritis.
  • In asymptomatic adults with iron deficiency anemia and plausible celiac disease, initial serologic testing, followed by small bowel biopsy only if positive, is suggested over routine small bowel biopsies.
  • In asymptomatic patients with uncomplicated iron deficiency anemia and negative results on bidirectional endoscopy, a trial of initial iron supplementation is suggested over the routine use of video capsule endoscopy.

Guidelines on assessment of iron deficiency anemia from the British Society of Gastroenterology include the following recommendations [19] :

  • Before investigation, iron deficiency should be confirmed via iron studies. Serum ferritin is the most useful iron deficiency anemia marker, but other blood tests (eg, transferrin saturation) can help if a false-normal ferritin is suspected. A good response to iron therapy (hemoglobin [Hb] rise ≥10 g/L within 2 wk) is highly suggestive of absolute iron deficiency, even if the results of iron studies are equivocal.
  • Initial investigation of confirmed iron deficiency anemia should include urinalysis or urine microscopy, screening for celiac disease, and, in appropriate cases, upper and lower gastrointestinal (GI) endoscopy. Celiac disease is found in 3-5% of iron deficiency anemia cases and should be routinely screened for serologically or on small-bowel biopsy at the time of gastroscopy.
  • Age, sex, Hb concentration, and mean cell volume are independent predictors of risk of GI cancer risk in iron deficiency anemia and must be considered as part of a holistic risk assessment. Fecal immunochemical testing cannot yet be recommended for risk stratification in iron deficiency anemia.
  • In men and postmenopausal women with newly diagnosed iron deficiency anemia, gastroscopy and colonoscopy should generally be the first-line GI investigations. Computed tomography (CT) colonography is a reasonable alternative in patients not suitable for colonoscopy.
  • Patients with negative bidirectional endoscopy and either an inadequate response to iron replacement therapy (IRT) or recurrent iron deficiency anemia should undergo further investigation of the small bowel and renal tract. Capsule endoscopy is the preferred test for examining the small bowel; in patients not suitable for this test, CT/magnetic resonance (MR) enterography may be considered. After negative capsule endoscopy, further GI investigation need be considered only for ongoing iron deficiency anemia after IRT. Long-term IRT may be appropriate if the cause of recurrent iron deficiency anemia is unknown or irreversible.

The British Society of Gastroenterology guidelines include the following recommendations on treatment of iron deficiency anemia [19] :

  • Initial treatment of iron deficiency anemia should be with one tablet of ferrous sulfate, fumarate, or gluconate q24hr. If this is not tolerated, a reduced dose (one tablet q48hr), alternative oral preparations, or parenteral iron should be considered.
  • Limited transfusion of packed red blood cells may on occasion be required to treat symptomatic iron deficiency anemia; IRT is still necessary after transfusion.
  • Patients should be monitored in the first 4 weeks for Hb response to oral iron, and treatment should be continued for ~3 months after normalization of the Hb level.
  • Parenteral iron should be considered when oral iron is contraindicated, ineffective, or not tolerated. Consideration should be at an early stage if oral IRT is judged unlikely to be effective or correction of iron deficiency anemia is particularly urgent.
  • After restoration of Hb and iron stores with IRT, the blood count should be monitored periodically (eg, every 6 months initially) to detect recurrence.
  • IRT should not be deferred while investigations for iron deficiency anemia are awaited, unless colonoscopy is imminent.