Iron Deficiency Anemia
Iron-Deficiency Anemia: GI Evaluation
Iron-deficiency anemia in adults often signals a GI source. Dr. Azaan Ramani, DO provides comprehensive evaluation across the Dallas–Fort Worth metroplex.
Iron-deficiency anemia (IDA) in adults — particularly men and post-menopausal women — should always prompt a GI evaluation. The British Society of Gastroenterology and American Gastroenterological Association both recommend bidirectional endoscopy (upper endoscopy plus colonoscopy) as the standard initial workup for unexplained IDA in adults.
Why GI Evaluation Matters
The GI tract is the most common source of occult blood loss in adults with IDA. Findings on workup can include:
- Colorectal cancer or advanced polyps — IDA can be the only presentation
- Gastric or esophageal cancer
- Peptic ulcer disease
- Celiac disease (impaired absorption)
- Esophagitis or gastritis (chronic blood loss)
- Vascular lesions (angiodysplasia)
- Inflammatory bowel disease
- Small bowel sources (e.g., Crohn's, NSAID enteropathy, vascular lesions, tumors)
Standard Workup
Confirm iron deficiency
- CBC: low Hb, low MCV (microcytic)
- Ferritin <30 ng/mL is highly specific for iron deficiency in most patients (threshold may be higher in inflammatory states)
- Iron studies: low serum iron, low transferrin saturation, elevated TIBC
- CRP if inflammation is suspected
Bidirectional endoscopy
The combination of upper endoscopy (EGD) and colonoscopy identifies a likely source in 60–70% of adult patients with unexplained IDA. Biopsies for celiac disease (duodenal biopsies) are routinely performed during EGD.
Small bowel evaluation
If bidirectional endoscopy is non-diagnostic and IDA persists or recurs, small bowel evaluation is the next step:
- Video capsule endoscopy — first-line non-invasive small bowel imaging
- CT or MR enterography — for suspected structural lesions
- Deep enteroscopy (single- or double-balloon) — when capsule identifies a treatable lesion
Treatment
Iron repletion
- Oral iron — first-line. Recent evidence supports alternate-day dosing (e.g., 60–120 mg elemental iron every other day) for better absorption and fewer GI side effects than daily dosing
- IV iron — for patients with malabsorption, intolerance, severe anemia, or ongoing significant blood loss
- Repeat labs at 2–4 weeks, then every 1–3 months until ferritin is replete
Treat the source
Definitive treatment depends on what's found — endoscopic polypectomy, treatment of H. pylori, gluten-free diet for celiac disease, IBD therapy, etc.
Special Populations
- Post-menopausal women: GI workup is required even with mild IDA
- Pre-menopausal women: gynecologic evaluation may come first, but GI workup is needed if there is no clear gynecologic source or if the anemia recurs
- Patients on aspirin, NSAIDs, or anticoagulants: still need full GI workup — these medications unmask underlying lesions rather than cause IDA on their own
- Celiac disease screening (anti-TTG IgA, total IgA) is recommended in all unexplained IDA
Iron-Deficiency Anemia: Common Questions
Why does my doctor want me to see a gastroenterologist for low iron?
In adults, iron-deficiency anemia is most often caused by chronic GI blood loss or impaired absorption. Standard workup is upper endoscopy plus colonoscopy to identify treatable sources — colon cancer, ulcers, celiac disease, vascular lesions. Treating iron without finding the source can mean missing a serious diagnosis.
Do I need both an upper endoscopy and colonoscopy?
Yes — AGA and BSG guidelines recommend bidirectional endoscopy (EGD plus colonoscopy) as initial workup for unexplained IDA in adults. The combination identifies a source in 60–70% of cases, typically performed under the same sedation.
What if my endoscopy and colonoscopy are normal?
If bidirectional endoscopy is non-diagnostic and IDA persists, next step is video capsule endoscopy for small bowel evaluation. CT or MR enterography may be added; deep enteroscopy treats capsule-identified lesions.
What's the best way to take iron supplements?
Alternate-day dosing (60–120 mg elemental iron every other day) provides better absorption and fewer GI side effects than daily dosing. Take with vitamin C; avoid calcium, antacids, coffee, and tea. Recheck labs in 2–4 weeks.
Can my iron pills cause stomach problems?
Yes — nausea, constipation, dark stools, and abdominal discomfort are common. Help with: alternate-day dosing, taking with food, switching formulations, or IV iron when oral is not tolerated.
Ready to schedule a consultation?
Dr. Ramani sees patients across the Dallas–Fort Worth area. Send a message and his team will be in touch.
Connect with Dr. Ramani →