Iron Deficiency Anemia in Northern Virginia

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Iron deficiency anemia is a low red blood cell count caused by a shortage of iron, and when it turns up on routine bloodwork without an obvious explanation, a referral to a gastroenterologist is a common next step. That referral can feel alarming if you came in for a checkup and left with a scope scheduled. The reason is practical: the digestive tract is one of the most common places the body loses iron or fails to absorb it, and some of those causes do not produce any symptoms you would notice. This guide explains how iron deficiency anemia is confirmed, why a gastroenterologist usually looks at both the upper and lower digestive tract, what other tests may follow, and how iron is replaced while the cause is found.

This article is general education, not medical advice. Your own evaluation depends on your age, health history, and test results, so talk with your physicians about what applies to you.

What iron deficiency anemia is

The National Heart, Lung, and Blood Institute (NHLBI) describes iron deficiency anemia as a type of anemia that develops when you do not have enough iron in your body, and notes that it is the most common type of anemia. Your body needs iron to make healthy red blood cells, which carry oxygen. When iron runs low, the body makes fewer red blood cells and less hemoglobin, the protein inside them that holds oxygen.

The American Gastroenterological Association (AGA) puts it simply in its patient materials: iron deficiency anemia means a low blood count together with not enough iron. Two things are true at once, and both matter. The anemia explains how you may feel. The iron shortage is a clue that points toward a cause.

Symptoms of iron deficiency anemia

Many people have none. The NHLBI notes that mild or moderate iron deficiency anemia may not cause any symptoms, which is why it is so often found on a blood test ordered for another reason. When symptoms do appear, the NHLBI lists these as common:

• Tiredness or fatigue
• Shortness of breath
• Dizziness or lightheadedness
• Cold hands and feet
• Pale skin
• Chest pain, with more serious anemia

Chest pain or significant shortness of breath deserves prompt medical attention, not a wait for an office visit. The NHLBI also notes that untreated iron deficiency anemia can lead to headaches, restless legs syndrome, heart problems, and pregnancy complications, and can make other chronic conditions harder to manage.

Why iron deficiency anemia leads to a gastroenterologist

Iron is lost when blood is lost, and it is gained only by absorbing it from food. The digestive tract sits at the center of both. That is why a primary care physician, gynecologist, or hematologist who confirms iron deficiency anemia without a clear cause will often refer the patient to a gastroenterologist.

The AGA's patient guidance states that iron deficiency anemia can be a sign of gastrointestinal cancer or of conditions that cause serious complications if left untreated. It also makes a point that surprises many people: ulcers, inflammation, cancer, and precancerous polyps can bleed in very small amounts over time, so you may never see blood in your stool. Slow, hidden bleeding is enough to drain iron stores month after month.

Common digestive causes of iron deficiency anemia

The NHLBI and the AGA list several digestive causes, which fall into two groups.

Slow blood loss. Bleeding in the digestive tract can come from ulcers, inflammatory bowel disease, colon polyps or colorectal cancer, and inflammation of the digestive lining. The NHLBI adds that regular use of aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, can lead to bleeding in the digestive tract.

Poor absorption. The NHLBI lists celiac disease, ulcerative colitis, Crohn's disease, and Helicobacter pylori infection as conditions that make it harder to absorb iron, along with surgery on the stomach and intestines, including weight loss surgery.

Causes outside the digestive tract matter too. The NHLBI lists heavy menstrual periods, bleeding during childbirth, urinary tract bleeding, kidney disease, and long-term inflammatory conditions, and the AGA notes that a diet low in iron, including some vegan or vegetarian diets, can contribute. Part of a gastroenterologist's job is to weigh how much each of these explains before deciding how far to look.

How iron deficiency anemia is confirmed

The NHLBI describes the diagnosis as a blood test: a complete blood count (CBC), hemoglobin, blood iron levels, and ferritin. Ferritin is the key number. It reflects how much iron your body has in storage, and a low ferritin in someone with anemia points strongly toward iron deficiency.

The ferritin cutoff for iron deficiency anemia

Where to draw the line has changed. In its 2020 clinical practice guideline on the gastrointestinal evaluation of iron deficiency anemia, the AGA recommends a ferritin cutoff of 45 ng/mL rather than 15 ng/mL when diagnosing iron deficiency in people with anemia. In plain terms, a ferritin between 15 and 45 in someone who is anemic can still indicate iron deficiency, even if a lab report flags it as low-normal rather than low. If you were told your ferritin is "borderline," it is worth asking whether that number was read against the AGA cutoff.

Bidirectional endoscopy for iron deficiency anemia

The central recommendation of the AGA guideline is that the digestive tract be examined from both ends. Gastroenterologists call this bidirectional endoscopy: an upper endoscopy (EGD) to view the esophagus, stomach, and first part of the small intestine, and a colonoscopy to view the colon and rectum. The two are often scheduled on the same day under the same sedation.

Looking at both ends matters because a cause in one place does not rule out a second cause in the other, and because the upper and lower tract harbor different culprits. An EGD can find ulcers, gastritis, and signs of celiac disease. A colonoscopy can find polyps, cancer, and inflammation of the colon.

Who the AGA recommends it for

The 2020 guideline makes two recommendations based on who the patient is. Both are written for people without symptoms that point to a specific cause.

• Men and postmenopausal women with iron deficiency anemia: the AGA recommends bidirectional endoscopy over no endoscopy.
• Premenopausal women with iron deficiency anemia: the AGA suggests bidirectional endoscopy over iron replacement alone. This is a conditional suggestion rather than a firm recommendation, which reflects a real clinical question. Menstrual blood loss is a common and sufficient explanation for many younger women, so the decision is individual and depends on factors such as family history, other symptoms, and how the anemia responds to iron.

If you have a family history of colorectal cancer, the timing of your evaluation may also connect to your screening plan. Our guide to family history and colon cancer screening explains how those decisions are made.

Preparing for both procedures

Preparation follows the colonoscopy, since the colon must be clean for a clear view. Our colonoscopy prep guide walks through the diet and laxative steps. Iron pills deserve a mention: many people with iron deficiency anemia are already taking them, and the instructions you receive may address when to pause them before a colonoscopy. Follow the written instructions from your physician's office, and ask if anything about your medications is unclear.

Other tests that may be part of the workup

The AGA guideline also addresses the tests that sit around endoscopy.

• Celiac testing. For adults with iron deficiency anemia in whom celiac disease is plausible, the AGA suggests starting with a blood test (serology) and taking small-bowel biopsies only if it is positive, rather than biopsying everyone routinely.
• H. pylori testing. If bidirectional endoscopy does not identify a cause, the AGA suggests noninvasive testing for H. pylori, followed by treatment if positive. Our guide to peptic ulcers and H. pylori covers how that testing works.
• Routine stomach biopsies. The AGA suggests against routine gastric biopsies to look for atrophic gastritis in people with iron deficiency anemia. Biopsies are still taken when something is seen that calls for them.

When both exams are normal

A normal upper endoscopy and colonoscopy is reassuring, because it rules out the most common serious causes. It does not always end the search, since the small intestine lies between the reach of the two scopes.

For people whose exams are normal and whose situation is otherwise uncomplicated, the AGA suggests a trial of iron supplementation over routine use of video capsule endoscopy. In other words, the first step is usually to replace iron and watch the response. If the anemia comes back, fails to improve, or there are other reasons for concern, a capsule study of the small intestine may then be recommended. Our capsule endoscopy guide explains how that test works and when it is used.

When a small-bowel source is found, the AGA's 2024 clinical practice update on managing iron deficiency anemia notes that small-bowel angioectasias, fragile blood vessels in the intestinal lining, can be treated endoscopically, and advises that such treatment be paired with iron replacement.

Treating iron deficiency anemia

Finding the cause and replacing the iron happen side by side. The NHLBI notes that oral iron is the most common treatment and that it often takes three to six months to restore iron levels. The AGA's 2024 clinical practice update offers practical advice on how to take it:

• No oral iron formulation has an advantage over another. The AGA prefers ferrous sulfate because it is the least expensive.
• Once a day at most. The AGA advises taking oral iron no more than once a day, and notes that every-other-day dosing may be easier to tolerate for some people, with similar absorption.
• Add vitamin C. The AGA advises taking vitamin C with oral iron to improve absorption. The NHLBI adds that black tea can reduce iron absorption.

Side effects are common and usually manageable. The NHLBI lists a metallic taste, upset stomach, constipation, diarrhea, and vomiting, and suggests talking with your doctor about taking iron with food, lowering the dose, or switching formulations. Iron also turns stool dark, which is expected. If constipation is a problem, our guide to chronic constipation may help.

When intravenous iron is used

The 2024 AGA update advises intravenous (IV) iron when oral iron is not tolerated, when ferritin does not improve with a trial of oral iron, or when a condition makes absorption unlikely. It specifically advises IV iron for people with iron deficiency anemia after bariatric procedures that disrupt absorption, and for people with inflammatory bowel disease whose active inflammation limits absorption. (Our IBD diet page explains the AGA advice to monitor iron and vitamin D in everyone with IBD.) It prefers formulations that replace the deficit in one or two infusions, and notes that true allergic reactions to IV iron are very rare. For people with celiac disease, it advises that strict adherence to a gluten-free diet is part of improving iron absorption.

Iron replacement treats the shortage, not its source. That is why it is paired with an evaluation, and why a gastroenterologist may want to recheck your blood counts and ferritin after treatment to confirm the response.

Signs that need prompt attention

Iron deficiency anemia is usually evaluated through a scheduled referral, but some signs call for faster care. Black, tarry stools, vomiting blood or material that looks like coffee grounds, visible rectal bleeding, fainting, chest pain, or significant shortness of breath can signal active bleeding or severe anemia and warrant same-day evaluation or an emergency department visit. Our guide to blood in the stool explains how different kinds of bleeding are assessed, and our guide to unexplained weight loss covers another symptom that often travels with anemia and deserves a timely look.

General patient information is available from the National Heart, Lung, and Blood Institute, and the American Gastroenterological Association publishes its guideline recommendations.

Evaluation for iron deficiency anemia in Northern Virginia with GC of NoVA

Gastroenterology Center of Northern Virginia sees patients across Arlington, Annandale, and the surrounding communities who have been referred for iron deficiency anemia, often by a primary care physician, gynecologist, or hematologist. Our physicians can review your bloodwork and history, talk through whether upper endoscopy and colonoscopy are recommended in your situation, coordinate celiac and H. pylori testing when they apply, and work with your other physicians on iron replacement while the cause is identified. We see patients at our Arlington office, next to VHC Health, and our Annandale office, in the Woodburn Medical complex. If this is your first visit with a gastroenterologist, our guide to your first gastroenterologist visit explains what to bring, including recent lab results.

To schedule an evaluation, contact our Arlington office at (703) 522-7476 or our Annandale office at (703) 560-6106, or learn more at gcofnova.com. If you have black stools, are vomiting blood, or feel faint or short of breath, seek emergency care.

This article is for general education and is not medical advice. Talk with a qualified gastroenterologist about your symptoms, diagnosis, and treatment options.