Essential Questions for Suspected Iron Deficiency Anemia with Potential GI Bleeding
When evaluating a patient with suspected iron deficiency anemia and potential gastrointestinal bleeding, your history must systematically exclude alternative causes before proceeding to invasive investigation, as the AGA guidelines emphasize that bidirectional endoscopy is only indicated when there is no other unequivocal explanation for the anemia. 1
Demographic and Baseline Information
Age and sex – This determines your diagnostic threshold and urgency, as postmenopausal women and men require bidirectional endoscopy regardless of symptoms, while premenopausal women under 40 may not need immediate endoscopy if menstrual losses explain the anemia 1, 2
Menopausal status in women – Menstrual blood loss is the most common cause of iron deficiency in premenopausal women, but does not exclude concurrent GI pathology, particularly in women over 40 1, 3
Blood Loss History
Gastrointestinal Symptoms
Visible blood in stool (melena or hematochezia) – Overt bleeding changes the diagnostic approach entirely 4, 2
Abdominal pain, dyspepsia, or reflux symptoms – These direct specific endoscopic investigation and may indicate peptic ulcer disease, erosive esophagitis, or inflammatory bowel disease 1
Change in bowel habits, diarrhea, or weight loss – Red flags for colorectal malignancy or inflammatory bowel disease that mandate urgent bidirectional endoscopy 3, 2
Non-GI Blood Loss
Menstrual history – Quantify duration, frequency, and heaviness of periods; ask specifically about clots or flooding, as heavy menstrual bleeding is the primary alternative explanation in premenopausal women 1
Urinary symptoms or hematuria – Urinalysis should be performed to exclude urinary tract bleeding as a source 3
Frequent blood donation – A well-recognized cause that must be explicitly asked about, as patients may not volunteer this information 1, 3
Medication History
NSAID use – Ask specifically about over-the-counter ibuprofen, naproxen, and aspirin, as patients often don't consider these "real medications" and NSAIDs are a common unreported cause of occult GI blood loss even without symptoms 3, 5
Anticoagulants and antiplatelet agents – These can unmask underlying vascular lesions like angiodysplasia 3
Proton pump inhibitors or H2 blockers – May indicate prior GI symptoms or peptic disease 6
Dietary and Nutritional Assessment
Dietary iron intake – Ask about consumption of red meat, poultry, fish, and iron-fortified foods; vegetarian or vegan diets increase risk of nutritional deficiency 1, 3
Symptoms of malabsorption – Chronic diarrhea, bloating, or steatorrhea suggest celiac disease or other malabsorptive disorders 1, 2
History of bariatric surgery – Gastric bypass or resection predisposes to iron deficiency through multiple mechanisms and requires lifelong monitoring 3
Screening for Celiac Disease Risk Factors
Family history of celiac disease – Celiac disease accounts for 3-5% of all iron deficiency anemia cases and must be screened for with tissue transglutaminase antibody (IgA type) and total IgA level 1, 7, 3, 2
Associated autoimmune conditions – Type 1 diabetes, thyroid disease, or other autoimmune disorders increase celiac disease risk 6
Chronic Disease Assessment
Chronic kidney disease – Ferritin levels may not accurately reflect iron stores in CKD; additional tests like transferrin saturation or C-reactive protein may be needed 1
Chronic inflammatory conditions – Rheumatoid arthritis, inflammatory bowel disease, or other inflammatory states can elevate ferritin despite true iron deficiency 1, 8
History of cancer treatment – Androgen deprivation therapy in prostate cancer causes anemia through suppression of erythropoiesis 3
Helicobacter pylori Risk Assessment
- Dyspepsia or prior peptic ulcer disease – The AGA suggests non-invasive testing for H. pylori followed by treatment if positive, as H. pylori gastritis is associated with iron deficiency even without bleeding 1, 6
Response to Prior Iron Therapy
Previous iron supplementation – Ask about adherence, formulation used, duration of therapy, and whether hemoglobin improved; failure to respond after 4 weeks suggests continued blood loss, malabsorption, or non-adherence 7, 4
Gastrointestinal side effects from oral iron – Nausea, constipation, or diarrhea may have limited adherence 7, 5
Critical Pitfalls to Avoid
Do not accept dietary deficiency as the sole explanation without completing GI investigation in men and postmenopausal women – Even with a positive dietary history, full GI evaluation is required as gastrointestinal malignancy must be excluded 7, 3, 4
Do not assume menstrual losses fully explain anemia in premenopausal women over 40 or those with alarm symptoms – These patients still require GI investigation 1, 3
Do not fail to ask specifically about over-the-counter NSAID use – Patients frequently omit this from their medication history, leading to missed diagnoses 3
Do not overlook celiac disease screening – This treatable cause is found in 3-5% of cases and is easily missed without serologic testing 1, 7, 3