The American Gastroenterological Association (AGA) has recently issued a set of guidelines for the GI evaluation of patients with iron deficiency anaemia (IDA). This article outlines the recommendations presented in the guidelines for clinical practice.

The AGA released a set of clinical practice guidelines on the gastrointestinal evaluation of iron deficiency anaemia (IDA). These guidelines were aimed to tackle the practice variability observed in the initial gastrointestinal evaluation of IDA. This, in addition to the uncertainty about parameters used for diagnosing iron deficiency, the type and order of diagnostic evaluation, and the use of investigations for various GI problems, lead to a lack of uniformity in clinical practice. These guidelines provide an evidence-based approach for the initial diagnosis and evaluation of the commonly encountered clinical conditions.

Recommendations

The recommendations made by the researchers were formed on the basis of the GRADE framework and the strength of the available evidence. Here we have outlined the recommendations under different levels and quality of evidence:

A. Strong recommendations based on high-quality evidence

1. In patients with anaemia, the AGA recommends using a limit of 45 ng/mL over 15 ng/mL while using ferritin to establish iron deficiency.

In patients who have inflammatory conditions or chronic kidney disease, additional laboratory tests like C-reactive protein, transferrin saturation, or soluble transferrin saturation may be combined along with ferritin to establish IDA.

2. In asymptomatic postmenopausal women and men with iron-deficiency anaemia, the AGA recommends bi-directional endoscopy in comparison to no endoscopy.

Generally, the presence of gastrointestinal malignancy in IDA shows that endoscopic evaluation will correctly identify malignancy and provide a potentially enhanced evaluation, particularly for colorectal cancer. Some other potential aetiologies, such as erosive esophagitis, peptic ulcer disease, coeliac disease, and inflammatory bowel disease can also be identified with bi-directional endoscopy. The benefits of detection of gastrointestinal disorders and malignancy in the studied patient population were considered to be more significant in comparison to the minor risks of bi-directional endoscopy.

B. Conditional recommendations based on moderate-quality evidence

3. In asymptomatic premenopausal women with IDA, bi-directional endoscopy is suggested in comparison to only iron replacement therapy.

For patients who want to avoid the minor risk of endoscopy, say young patients who may have other reasons for IDA, and those who can accept the minor risk of missing a gastrointestinal malignancy could judiciously choose a course of iron replacement therapy and go without the initial bi-directional endoscopy.

4. For patients with IDA in absence of other recognisable aetiology post-bi-directional endoscopy, the AGA suggests non-invasive testing for H. pylori, and if found positive, treatment compared to no testing.
5. The AGA advises against the use of regular gastric biopsies to identify atrophic gastritis in patients with IDA.
6. For adult patients with iron deficiency anaemia and probable coeliac disease, the AGA advises serologic testing, to begin with, and only if positive, to be followed by small bowel biopsy in comparison to regular small bowel biopsies.

The reviewing panel further commented that coeliac disease is known to cause iron deficiency anaemia; even in patients with no symptoms it is commonplace and thus, it must be given consideration in identifying iron deficiency anaemia.

7. For patients with simple asymptomatic iron deficiency anaemia and negative bi-directional endoscopy, the AGA advises to try out iron supplementation instead of the commonly used video capsule endoscopy.

As per the reviewing panel, careful attention should be paid to patients with comorbidities, especially where the detection of small bowel pathology can demand altered medical management of the problem.

Recommendations for iron supplementation in IDA patients

This topic lays outside the scope of this guideline and therefore, there is no formal recommendation on it. However, clinicians are reminded that there are several oral and intravenous iron formulations available with varying costs and side effects and that there is no concrete evidence that suggests if either of the available formulae has a higher efficacy or is better tolerated by patients.

It is advised to prescribe iron supplements with regular food or enteric-coated formulations. Also, taking vitamin C should be advised to improve oral absorption of iron supplements. Intravenous iron supplements would be more suited for patients, who may have reduced absorption due to any previous gastric operation, or are suffering from inflammatory bowel disease or chronic kidney disease, or in whom blood loss has been too much to allow repletion of iron orally.

A large gap is evident in considering the results and appropriate techniques of small bowel investigation for patients with negative bi-directional endoscopy. Specifically created studies for the diagnostic results of video capsule endoscopy and comparative studies of outcomes of initial iron replacement vs small-bowel investigation would be instrumental in shaping further practices.

There is also a lack of evidence on the role of foecal occult blood testing when compared to the efficacy of various methods that can be used for small bowel investigation. So, future studies that are based on specifically defined sub-cohorts of patients for small-bowel investigation would be needed.