{
  "schemaVersion": 2,
  "eyebrow": "Gastroenterology",
  "title": "Iron Deficiency Anemia Gastrointestinal Evaluation",
  "summary": "Confirm iron deficiency before attributing anemia to gastrointestinal blood loss, then use patient sex, menopausal status, symptoms, and initial endoscopic findings to select bidirectional endoscopy, celiac testing, noninvasive infection testing, or small-bowel evaluation.",
  "seoDescription": "A physician-focused approach to gastrointestinal evaluation of iron deficiency anemia, including ferritin interpretation, endoscopy, celiac testing, and capsule endoscopy.",
  "clinicalQuestion": "Which adults with iron deficiency anemia require gastrointestinal evaluation, and how should testing proceed after negative initial endoscopy?",
  "specialty": "Gastroenterology",
  "audience": "U.S. physicians and medical trainees",
  "tags": [
    "iron deficiency anemia",
    "gastrointestinal evaluation",
    "bidirectional endoscopy",
    "celiac disease",
    "capsule endoscopy",
    "occult gastrointestinal bleeding"
  ],
  "keyTakeaways": [
    "Establish iron deficiency with ferritin and transferrin saturation before assigning gastrointestinal blood loss; ferritin below 15 µg/L indicates absent stores, while ferritin at or below 30 µg/L improves sensitivity for iron deficiency while retaining high specificity. [1][22]",
    "Adult men and postmenopausal women with iron deficiency anemia should generally undergo both upper endoscopy and colonoscopy because chronic occult gastrointestinal bleeding is a frequent cause and clinically important lesions may be asymptomatic. [12][18]",
    "Order celiac serology in every adult with iron deficiency anemia; consider autoimmune gastritis and Helicobacter pylori assessment, particularly after an inadequate response to oral iron. [12]",
    "After negative EGD and colonoscopy, reserve small-bowel capsule endoscopy for persistent or recurrent iron deficiency anemia or suspected obscure gastrointestinal bleeding; the small bowel becomes the principal anatomic target after adequate negative bidirectional endoscopy. [8][10]"
  ],
  "sections": [
    {
      "id": "confirm-iron-deficiency",
      "eyebrow": "First decision",
      "heading": "Confirm iron deficiency before gastrointestinal investigation",
      "intro": "Use iron indices to separate absolute deficiency from inflammation-associated iron restriction.",
      "paragraphs": [
        "Obtain CBC, ferritin, and transferrin saturation (TSAT) before labeling anemia as gastrointestinal blood loss. In the absence of inflammation, ferritin is the most specific marker: ferritin below 15 µg/L indicates absent iron stores, and values below 30 µg/L generally indicate low body iron stores. A ferritin threshold of 30 µg/L has reported sensitivity of 92% and specificity of 98% for iron deficiency. [1][22]",
        "Do not exclude iron deficiency solely because ferritin is not low in chronic inflammatory conditions. Ferritin is an acute-phase reactant; in chronic heart failure, chronic kidney disease, or inflammatory bowel disease, ferritin below 100 µg/L or TSAT below 20% can support iron deficiency. In chronic inflammatory conditions, TSAT below 20% is commonly used to identify patients likely to benefit from iron replacement. [14][20]",
        "A microcytic, hypochromic anemia with a low absolute reticulocyte count and ferritin below 15 µg/L is the classic pattern of absolute iron deficiency. When ferritin is equivocal, low TSAT, reticulocyte hemoglobin, soluble transferrin receptor, percentage hypochromic red cells, or red-cell zinc protoporphyrin can strengthen the diagnosis and prevent unnecessary invasive gastrointestinal testing for a non–iron-deficient anemia. [1][23]"
      ],
      "bullets": [
        "Ferritin <15 µg/L: absent iron stores; proceed to cause assessment after confirming the clinical context. [1]",
        "Ferritin ≤30 µg/L: supports iron deficiency with greater sensitivity than the 15 µg/L threshold. [22]",
        "Inflammatory disease with ferritin <100 µg/L or TSAT <20%: consider concomitant iron deficiency rather than attributing anemia to inflammation alone. [14][20]"
      ],
      "subsections": [],
      "table": {
        "caption": "Iron-study patterns that change the gastrointestinal evaluation threshold. [1][14][20][22]",
        "columns": [
          "Clinical setting",
          "Actionable iron-study finding",
          "Interpretation and next step"
        ],
        "rows": [
          [
            "No evident inflammation",
            "Ferritin <15 µg/L",
            "Absent iron stores; evaluate for the source of iron loss or impaired absorption. [1]"
          ],
          [
            "No evident inflammation",
            "Ferritin ≤30 µg/L",
            "Iron deficiency is likely; assess menstrual, dietary, malabsorptive, and gastrointestinal bleeding pathways. [22]"
          ],
          [
            "CHF, CKD, or IBD",
            "Ferritin <100 µg/L or TSAT <20%",
            "Iron deficiency can coexist with inflammation; interpret the anemia as potentially iron responsive and assess cause. [14]"
          ],
          [
            "Chronic inflammatory condition",
            "TSAT <20%",
            "Supports restricted available iron when ferritin is difficult to interpret; use clinical context and evaluate for blood loss when indicated. [20]"
          ]
        ]
      }
    },
    {
      "id": "triage-for-urgent-bleeding",
      "eyebrow": "Urgency",
      "heading": "Separate chronic occult loss from overt or clinically unstable bleeding",
      "intro": "Visible bleeding or instability changes the sequence from elective anemia evaluation to bleeding-source localization and treatment.",
      "paragraphs": [
        "Iron deficiency anemia often reflects chronic occult gastrointestinal bleeding, particularly in adult men and postmenopausal women. Grossly normal stool does not exclude clinically important blood loss: patients losing approximately 100 mL of blood daily may have no visible stool change. [18]",
        "Melena, hematochezia, recurrent overt bleeding, hemodynamic instability, or transfusion requirement should be managed as gastrointestinal bleeding rather than as routine outpatient iron deficiency anemia. In patients with negative initial endoscopic assessment and instability or transfusion need, capsule endoscopy has been completed within 48 hours in emergency evaluations, but this is a distinct obscure-bleeding pathway rather than the default workup for uncomplicated anemia. [9]",
        "Do not use fecal occult blood testing to decide whether an iron-deficient adult merits evaluation. Occult bleeding and iron deficiency anemia lie on a spectrum of intermittent or chronic bleeding from benign or malignant gastrointestinal lesions, and anemia may be the only presenting manifestation. [7][18]"
      ],
      "bullets": [
        "Overt melena or hematochezia: prioritize bleeding evaluation and lesion-directed management over a staged outpatient anemia workup. [7][9]",
        "Persistent iron deficiency anemia without visible bleeding: evaluate for occult gastrointestinal blood loss after confirming iron deficiency. [18]",
        "Normal-appearing stool: does not exclude substantial chronic gastrointestinal blood loss. [18]"
      ],
      "subsections": [],
      "table": {
        "caption": "Presentation-based sequencing of gastrointestinal evaluation. [7][9][18]",
        "columns": [
          "Presentation",
          "Working pathway",
          "Immediate next action"
        ],
        "rows": [
          [
            "Iron deficiency anemia without overt bleeding",
            "Occult gastrointestinal blood loss or impaired absorption",
            "Confirm iron deficiency, determine risk group, and plan etiologic evaluation. [18]"
          ],
          [
            "Melena or hematochezia with iron deficiency",
            "Overt gastrointestinal bleeding",
            "Use bleeding-directed endoscopic assessment rather than relying on stool testing. [7]"
          ],
          [
            "Negative initial endoscopy plus instability or transfusion need",
            "Obscure gastrointestinal bleeding",
            "Consider expedited capsule endoscopy after negative endoscopic assessment. [9]"
          ]
        ]
      }
    },
    {
      "id": "initial-endoscopic-evaluation",
      "eyebrow": "Core diagnostic branch",
      "heading": "Select bidirectional endoscopy by gastrointestinal risk",
      "intro": "The principal decision is whether anemia warrants both upper and lower tract examination despite absent localizing symptoms.",
      "paragraphs": [
        "Refer adult men and postmenopausal women with confirmed iron deficiency anemia for upper and lower gastrointestinal endoscopy unless a competing explanation clearly outweighs procedural benefit. These groups have a high risk of bleeding gastrointestinal lesions, and adult male and postmenopausal iron deficiency anemia is frequently attributable to chronic occult gastrointestinal bleeding. [12][18]",
        "Bidirectional endoscopy means EGD plus colonoscopy. Upper and lower endoscopy identify the cause of bleeding in approximately 70% to 80% of patients with iron deficiency anemia in the cited review literature, supporting examination of both tracts rather than symptom-directed single-site testing in higher-risk adults. [8]",
        "In premenopausal women, first establish whether there is a clear non-gastrointestinal explanation. Consider bidirectional endoscopy when gastrointestinal symptoms are present, bowel habits have changed, overt bleeding occurs, there is a personal history of colorectal cancer or a first-degree relative with colorectal cancer, or no clear explanation for iron deficiency anemia exists. [12]",
        "Do not defer evaluation in a man or postmenopausal woman because iron replacement improves hemoglobin. Replacement corrects the deficit but does not exclude a bleeding lesion or malabsorptive disorder. In patients with heart failure and absolute iron deficiency, coordinate procedural necessity and safety with cardiology when endoscopic evaluation is being considered. [1]"
      ],
      "bullets": [
        "Adult men: bidirectional endoscopy is generally indicated after iron deficiency anemia is confirmed. [12][18]",
        "Postmenopausal women: bidirectional endoscopy is generally indicated after iron deficiency anemia is confirmed. [12][18]",
        "Premenopausal women: use symptoms, overt bleeding, colorectal cancer history, family history, and absence of an alternative explanation to lower the threshold for bidirectional endoscopy. [12]",
        "Heart failure with absolute iron deficiency: coordinate endoscopic risk and timing with cardiology. [1]"
      ],
      "subsections": [
        {
          "heading": "What a negative examination means",
          "paragraphs": [
            "A negative EGD and colonoscopy define a potential obscure gastrointestinal bleeding phenotype only when iron deficiency anemia persists or recurs. After adequate negative bidirectional endoscopy, the small bowel becomes the principal target for further investigation rather than repeating nonspecific fecal testing. [8]"
          ],
          "bullets": []
        }
      ],
      "table": {
        "caption": "Who should proceed to bidirectional endoscopy for iron deficiency anemia. [1][12][18]",
        "columns": [
          "Patient group",
          "Endoscopic threshold",
          "Decision modifiers"
        ],
        "rows": [
          [
            "Adult men",
            "Consider EGD plus colonoscopy",
            "Chronic occult gastrointestinal bleeding is a common cause of iron deficiency anemia in this group. [12][18]"
          ],
          [
            "Postmenopausal women",
            "Consider EGD plus colonoscopy",
            "High risk of bleeding gastrointestinal lesions warrants upper and lower tract assessment. [12]"
          ],
          [
            "Premenopausal women",
            "Consider EGD plus colonoscopy when risk modifiers are present",
            "Gastrointestinal symptoms, altered bowel habit, overt bleeding, personal colorectal cancer history, first-degree colorectal cancer history, or no clear alternate explanation favor evaluation. [12]"
          ],
          [
            "Heart failure with absolute iron deficiency",
            "Consider EGD plus colonoscopy",
            "Make the need for and safety of endoscopy jointly with cardiology. [1]"
          ]
        ]
      }
    },
    {
      "id": "malabsorption-and-gastric-causes",
      "eyebrow": "Nonbleeding causes",
      "heading": "Test for celiac disease and evaluate gastric causes of impaired iron acquisition",
      "intro": "Endoscopy does not replace targeted evaluation for enteropathy or gastric disorders that impair iron absorption.",
      "paragraphs": [
        "Order celiac serology for every adult with iron deficiency anemia. Tissue transglutaminase IgA is the serologic test addressed in the AGA technical review; interpret it in the context of total IgA status when clinical suspicion remains despite negative testing. A positive result redirects the evaluation toward celiac disease as a cause of iron malabsorption and supports upper gastrointestinal assessment with appropriate diagnostic sampling. [12][21]",
        "Consider celiac serology even in nonanemic iron deficiency. This is particularly important when gastrointestinal symptoms are absent because iron deficiency may be the presenting consequence of reduced proximal small-bowel iron absorption. [12]",
        "Assess for Helicobacter pylori infection and autoimmune gastritis, particularly when oral iron produces an inadequate response. These disorders should be considered alongside ongoing occult blood loss after negative or nondiagnostic initial endoscopy, rather than repeatedly escalating endoscopic testing without reassessing absorption. [12]",
        "When oral iron is contraindicated, ineffective, or not tolerated, consider parenteral iron while the etiologic workup continues. Monitor for an adequate hematologic response; persistent deficiency despite replacement is an escalation trigger for reassessing adherence, ongoing blood loss, celiac disease, H. pylori, autoimmune gastritis, and the adequacy of prior endoscopic examinations. [24][12]"
      ],
      "bullets": [
        "All adults with iron deficiency anemia: obtain celiac serology. [12]",
        "Nonanemic iron deficiency: consider celiac serology when determining cause. [12]",
        "Inadequate response to oral iron: reassess for H. pylori infection and autoimmune gastritis. [12]",
        "Oral iron contraindicated, ineffective, or not tolerated: consider parenteral iron and monitor response. [24]"
      ],
      "subsections": [],
      "table": {
        "caption": "Testing beyond routine endoscopy when impaired absorption remains plausible. [12][21][24]",
        "columns": [
          "Clinical clue",
          "Test or action",
          "What the result changes"
        ],
        "rows": [
          [
            "Any adult with iron deficiency anemia",
            "Celiac serology, including tissue transglutaminase IgA–based evaluation",
            "Identifies a malabsorptive cause and redirects management toward celiac disease evaluation. [12][21]"
          ],
          [
            "Nonanemic iron deficiency",
            "Consider celiac serology",
            "May identify celiac disease before anemia develops. [12]"
          ],
          [
            "Inadequate oral iron response",
            "Assess for H. pylori and autoimmune gastritis",
            "Identifies gastric causes of impaired iron acquisition requiring cause-directed management. [12]"
          ],
          [
            "Oral iron cannot be used effectively",
            "Use parenteral iron and monitor hematologic response",
            "Restores iron while investigation for bleeding or malabsorption proceeds. [24]"
          ]
        ]
      }
    },
    {
      "id": "after-negative-bidirectional-endoscopy",
      "eyebrow": "Escalation",
      "heading": "Use capsule endoscopy for persistent or recurrent anemia after adequate negative EGD and colonoscopy",
      "intro": "Small-bowel testing is an escalation step, not the routine first examination for iron deficiency anemia.",
      "paragraphs": [
        "After negative EGD and colonoscopy, determine whether iron deficiency anemia has resolved with replacement or remains persistent or recurrent. Persistent or recurrent iron deficiency anemia after negative initial endoscopy fits occult obscure gastrointestinal bleeding, for which the small bowel is the next anatomic target. [8]",
        "Use video capsule endoscopy to detect small-bowel mucosal abnormalities when the small bowel is the suspected source. In older adults with iron deficiency anemia and overt obscure bleeding, angiodysplasia was the most common reported capsule finding among patients older than 85 years; erosions and ulcerations were common findings across age groups. [10]",
        "Recognize factors associated with a higher likelihood of positive capsule findings: age above 60 years, previous bleeding episodes, transfusion requirement, inflammatory bowel disease, and repeat capsule evaluation after an initially nondiagnostic study. These features can justify earlier small-bowel escalation in recurrent or clinically consequential disease. [9]",
        "Capsule endoscopy does not provide therapy. Use a positive study to direct lesion-specific enteroscopy or other targeted management rather than treating the capsule finding as an endpoint. If prior endoscopy quality or completeness was inadequate, reassess the original examinations before assigning the bleeding source to the small bowel. [8]"
      ],
      "bullets": [
        "Adequate negative EGD and colonoscopy plus recurrent or persistent iron deficiency anemia: pursue small-bowel evaluation, commonly with capsule endoscopy. [8]",
        "Age >60 years, prior bleeding, transfusion requirement, inflammatory bowel disease, or a prior nondiagnostic capsule: higher-yield capsule phenotype. [9]",
        "Capsule-detected lesion: use findings to plan targeted diagnostic or therapeutic enteroscopy. [8]"
      ],
      "subsections": [],
      "table": {
        "caption": "Escalation after negative bidirectional endoscopy. [8][9][10]",
        "columns": [
          "Post-endoscopy status",
          "Next decision",
          "Rationale"
        ],
        "rows": [
          [
            "Iron deficiency anemia resolves with replacement",
            "Monitor for recurrence and continue cause-directed management",
            "Small-bowel testing is principally relevant for persistent or recurrent anemia after negative initial evaluation. [8]"
          ],
          [
            "Persistent or recurrent iron deficiency anemia",
            "Evaluate the small bowel with capsule endoscopy",
            "The small bowel is the principal target after negative EGD and colonoscopy. [8]"
          ],
          [
            "Recurrent bleeding with age >60 years, transfusion need, IBD, or prior bleeding episodes",
            "Lower threshold for capsule evaluation",
            "These factors predict a greater likelihood of positive capsule findings. [9]"
          ],
          [
            "Capsule identifies erosion, ulcer, or angiodysplasia",
            "Plan lesion-directed enteroscopic evaluation or treatment",
            "Capsule detects mucosal abnormalities but is not therapeutic. [8][10]"
          ]
        ]
      }
    }
  ],
  "faq": [
    {
      "question": "Should iron replacement be delayed until gastrointestinal evaluation is complete?",
      "answer": "No. Treat iron deficiency while the source evaluation proceeds, but do not regard hematologic improvement as evidence that gastrointestinal investigation is unnecessary in higher-risk adults. Use parenteral iron when oral iron is contraindicated, ineffective, or not tolerated, and monitor for adequate response. [12][24]"
    },
    {
      "question": "When is repeat capsule endoscopy reasonable after a negative study?",
      "answer": "A repeat capsule study may be considered after diagnostic failure of the initial study, particularly when iron deficiency anemia or bleeding recurs and the patient has higher-yield features such as age above 60 years, prior bleeding episodes, transfusion requirement, or inflammatory bowel disease. [9]"
    }
  ],
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      "url": "https://www.nejm.org/doi/full/10.1056/NEJM200001133420202",
      "authors": "www.nejm.org",
      "host": "www.nejm.org",
      "snippet": "Residual iron-deficiency anemia was treated with iron supplements and foods high in iron content. Colonoscopy for the Diagnosis",
      "score": 0.502564
    },
    {
      "number": 4,
      "title": "Young-onset colorectal cancer | Nature Reviews Disease Primers",
      "detail": "www.nature.com",
      "url": "https://www.nature.com/articles/s41572-023-00432-7",
      "authors": "www.nature.com",
      "host": "www.nature.com",
      "snippet": "Article \nPubMed \nGoogle Scholar\n\nGiardiello, F. M. et al. Guidelines on genetic evaluation and management of Lynch syndrome: a consensus statement by the US Multi-society Task Force on colorectal cancer. Am. J. Gastroenterol. 109, 1159–1179 (2014).\n\nArticle \nPubMed \nGoogle Scholar\n\nKnudsen, A. B. et",
      "score": 0.6538572
    },
    {
      "number": 5,
      "title": "A clinical study evaluating low dose ferrous fumarate vs. standard iron supplements in iron-deficient non-anemic to mild anemic adults | Scientific Reports",
      "detail": "www.nature.com",
      "url": "https://www.nature.com/articles/s41598-024-65878-5",
      "authors": "www.nature.com",
      "host": "www.nature.com",
      "snippet": "Anaemia in women and children. WHO 2019. \n\nWarner, M. J. & M. T. Kamran. Iron Deficiency Anemia. StatPearls, StatPearls Publishing, 7 (2023).\n\nSnook, J. et al. British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults. Gut 70(11), 2030–2051.  (2021).\n\nArt",
      "score": 0.39270994
    },
    {
      "number": 6,
      "title": "Diagnosis of chronic anaemia in gastrointestinal disorders: A guideline by the Italian Association of Hospital Gastroenterologists and Endoscopists (AIGO) and the Italian Society of Paediatric Gastroenterology Hepatology and Nutrition (SIGENP) - ScienceDirect",
      "detail": "www.sciencedirect.com",
      "url": "https://www.sciencedirect.com/science/article/abs/pii/S1590865819300581",
      "authors": "www.sciencedirect.com",
      "host": "www.sciencedirect.com",
      "snippet": "### Gastrointest Endosc\n\n### AGA technical review on the evaluation and management of occult and obscure gastrointestinal bleeding\n\n### Gastroenterology\n\n### Colonoscopy identifies increased prevalence of large polyps or tumors in patients 40–49 years old with hematochezia vs other gastrointestinal ",
      "score": 0.72605723
    },
    {
      "number": 7,
      "title": "American Gastroenterological Association medical position statement: Evaluation and management of occult and obscure gastrointestinal bleeding",
      "detail": "www.sciencedirect.com",
      "url": "https://www.sciencedirect.com/science/article/pii/S001650850070429X",
      "authors": "www.sciencedirect.com",
      "host": "www.sciencedirect.com",
      "snippet": "## Section snippets\n\n## Occult bleeding\n\nA review of occult bleeding studies finds similarities between cases that are predominantly FOBT positive2, 3 and those that are predominantly anemic with iron deficiency.4, 5, 6 Therefore, these two presentations probably represent a continuum of the same cl",
      "score": 0.70702106
    },
    {
      "number": 8,
      "title": "Obscure gastrointestinal bleeding and iron-deficiency anemia—Where does capsule endoscopy fit? - ScienceDirect",
      "detail": "www.sciencedirect.com",
      "url": "https://www.sciencedirect.com/science/article/abs/pii/S1096288315000108",
      "authors": "www.sciencedirect.com",
      "host": "www.sciencedirect.com",
      "snippet": "### Gastroenterol Clin North Am (2007) \n   A.F. Goddard _et al._\n### Guidelines for the management of iron deficiency anaemia\n\n### Gut (2011) \n   ASGE Standards of Practice Committee _et al._\n### The role of endoscopy in the management of obscure GI bleeding\n\n### Gastrointest Endosc (2010) \n   S.D. ",
      "score": 0.6172364
    },
    {
      "number": 9,
      "title": "Factors Associated With Positive Findings From Capsule Endoscopy in Patients With Obscure Gastrointestinal Bleeding - ScienceDirect",
      "detail": "www.sciencedirect.com",
      "url": "https://www.sciencedirect.com/science/article/abs/pii/S1542356512010397",
      "authors": "www.sciencedirect.com",
      "host": "www.sciencedirect.com",
      "snippet": "### The management of lower gastrointestinal bleeding\n\nCurrent recommendations suggest that a second VCE may be proposed after diagnostic failure of the initial study [24][29]. For obscure LGI bleeding, significant predictors of a positive VCE study were: age >60 years, previous episodes of bleeding,",
      "score": 0.5769478
    },
    {
      "number": 10,
      "title": "Evaluation of Iron Deficiency Anemia in Older... : Journal of Clinical Gastroenterology",
      "detail": "journals.lww.com",
      "url": "https://journals.lww.com/jcge/fulltext/2009/08000/evaluation_of_iron_deficiency_anemia_in_older.6.aspx",
      "authors": "journals.lww.com",
      "host": "journals.lww.com",
      "snippet": "Title: Evaluation of Iron Deficiency Anemia in Older... : Journal of Clinical Gastroenterology\n# Evaluation of Iron Deficiency Anemia in Older Adults. ## The Role of Wireless Capsule Endoscopy. Anemia although a frequent problem in all age groups, is an important cause of morbidity and mortality in ",
      "score": 0.568057
    },
    {
      "number": 11,
      "title": "Top Scoring Abstracts of the RCOG World Congress 2025",
      "detail": "obgyn.onlinelibrary.wiley.com",
      "url": "https://obgyn.onlinelibrary.wiley.com/doi/10.1111/1471-0528.18215",
      "authors": "obgyn.onlinelibrary.wiley.com",
      "host": "obgyn.onlinelibrary.wiley.com",
      "snippet": "Inclusion criteria focused on pregnant women with iron deficiency or anaemia who received oral iron supplementation, with response assessed",
      "score": 0.059850052
    },
    {
      "number": 12,
      "title": "Recommendations for diagnosis, treatment, and prevention of iron deficiency and iron deficiency anemia - Iolascon - 2024 - HemaSphere - Wiley Online Library",
      "detail": "onlinelibrary.wiley.com",
      "url": "https://onlinelibrary.wiley.com/doi/10.1002/hem3.108",
      "authors": "onlinelibrary.wiley.com",
      "host": "onlinelibrary.wiley.com",
      "snippet": "Iron deficiency is the presenting manifestation of various pathological processes, and investigation to exclude serious pathology and define the underlying cause is essential. Serological testing for coeliac disease should be considered in patients with nonanemic ID and is recommended for all adult ",
      "score": 0.65676886
    },
    {
      "number": 13,
      "title": "Iron deficiency anemia in older adults: A review - Wiley Online Library",
      "detail": "onlinelibrary.wiley.com",
      "url": "https://onlinelibrary.wiley.com/doi/10.1111/ggi.13194",
      "authors": "onlinelibrary.wiley.com",
      "host": "onlinelibrary.wiley.com",
      "snippet": "ferritin is the most frequently used diagnostic. A transferrin saturation <20% and other laboratory analyses, such as reticulocyte hemoglobin",
      "score": 0.6562404
    },
    {
      "number": 14,
      "title": "Limitations of Serum Ferritin in Diagnosing Iron Deficiency in ...",
      "detail": "onlinelibrary.wiley.com",
      "url": "https://onlinelibrary.wiley.com/doi/10.1155/2018/9394060",
      "authors": "onlinelibrary.wiley.com",
      "host": "onlinelibrary.wiley.com",
      "snippet": "A serum ferritin threshold of <100 μg/L or TSAT < 20% can be considered diagnostic for iron deficiency in CHF, CKD, and IBD. If serum ferritin",
      "score": 0.52510154
    },
    {
      "number": 15,
      "title": "Luminal Clinical - 2022 - Journal of Gastroenterology and Hepatology",
      "detail": "onlinelibrary.wiley.com",
      "url": "https://onlinelibrary.wiley.com/doi/10.1111/jgh.15955",
      "authors": "onlinelibrary.wiley.com",
      "host": "onlinelibrary.wiley.com",
      "snippet": "Laboratory testing confirmed an ongoing iron deficiency anemia, with ... iron studies, vitamin B12 and folate levels, and celiac serology.",
      "score": 0.51105833
    },
    {
      "number": 16,
      "title": "AGA Clinical Practice Guidelines on the Gastrointestinal Evaluation of Iron Deficiency Anemia - Gastroenterology",
      "detail": "www.gastrojournal.org",
      "url": "https://www.gastrojournal.org/article/S0016-5085(21)00470-4/abstract",
      "authors": "www.gastrojournal.org",
      "host": "www.gastrojournal.org",
      "snippet": "Title: AGA Clinical Practice Guidelines on the Gastrointestinal Evaluation of Iron Deficiency Anemia - Gastroenterology\n# AGA Clinical Practice Guidelines on the Gastrointestinal Evaluation of Iron Deficiency Anemia. AGA Clinical Practice Guidelines on the Gastrointestinal Evaluation of Iron Deficie",
      "score": 0.86331123
    },
    {
      "number": 17,
      "title": "AGA Clinical Practice Guidelines on the Gastrointestinal Evaluation of Iron Deficiency Anemia",
      "detail": "www.gastrojournal.org",
      "url": "https://www.gastrojournal.org/article/S0016-5085(20)34847-2/fulltext",
      "authors": "www.gastrojournal.org",
      "host": "www.gastrojournal.org",
      "snippet": "Title: AGA Clinical Practice Guidelines on the Gastrointestinal Evaluation of Iron Deficiency Anemia\n34847-2/fulltext# \"Close login popup\"). ## Login to your account. Your email address is a required field. Your password is a required field. Login with your AGA username and password. 34847-2/fulltex",
      "score": 0.8201387
    },
    {
      "number": 18,
      "title": "AGA Technical Review on Gastrointestinal Evaluation of Iron Deficiency Anemia - PMC",
      "detail": "www.ncbi.nlm.nih.gov",
      "url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10824166",
      "authors": "www.ncbi.nlm.nih.gov",
      "host": "www.ncbi.nlm.nih.gov",
      "snippet": "Iron deficiency anemia (IDA) is the commonest cause of anemia in the United States and worldwide. In the United States, it has been estimated that some 5%–11% of women and 1%–4% of men are iron deficient, and approximately 5% and 2%, respectively, have IDA.1 Although the cause of IDA may include ina",
      "score": 0.7783298
    },
    {
      "number": 19,
      "title": "AGA Clinical Practice Guidelines on the Gastrointestinal Evaluation ...",
      "detail": "www.gastrojournal.org",
      "url": "https://www.gastrojournal.org/article/S0016-5085(20)35616-X/pdf",
      "authors": "www.gastrojournal.org",
      "host": "www.gastrojournal.org",
      "snippet": "The data from these studies showed that a ferritin threshold of 15 mg/L for the diagnosis of iron deficiency anemia was specific (98%, 98%, and 100% for",
      "score": 0.7393665
    },
    {
      "number": 20,
      "title": "Diagnosis and management of iron deficiency in chronic ...",
      "detail": "ashpublications.org",
      "url": "https://ashpublications.org/hematology/article/2020/1/478/474369/Diagnosis-and-management-of-iron-deficiency-in",
      "authors": "ashpublications.org",
      "host": "ashpublications.org",
      "snippet": "Transferrin saturation (TSAT) <6% in combination with low ferritin is diagnostic of ID, but in the presence of inflammation, a seemingly arbitrary TSAT <20% is often used to diagnose ID. Because there is a significant overlap in ferritin levels between samples with BMID and normal BM iron (range, 50",
      "score": 0.55998856
    },
    {
      "number": 21,
      "title": "AGA Technical Review on Gastrointestinal Evaluation of Iron ...",
      "detail": "www.gastrojournal.org",
      "url": "https://www.gastrojournal.org/article/S0016-5085(20)34846-0/fulltext",
      "authors": "www.gastrojournal.org",
      "host": "www.gastrojournal.org",
      "snippet": "We aimed to define the diagnostic accuracy of ferritin cutoffs, as well as tissue transglutaminase (TTG) IgA antibodies to diagnose celiac",
      "score": 0.5440511
    },
    {
      "number": 22,
      "title": "Management of iron deficiency | Hematology, ASH Education Program",
      "detail": "ashpublications.org",
      "url": "https://ashpublications.org/hematology/article/2019/1/315/422602/Management-of-iron-deficiency",
      "authors": "ashpublications.org",
      "host": "ashpublications.org",
      "snippet": "However, a threshold of ferritin ≤30 μg/L achieves a higher sensitivity (92%) while maintaining a high 98% specificity for the diagnosis and is",
      "score": 0.49318945
    },
    {
      "number": 23,
      "title": "Acquired underproduction anemias: anemias in the setting of ...",
      "detail": "ashpublications.org",
      "url": "https://ashpublications.org/books/book/10/chapter/12743898/Acquired-underproduction-anemias-anemias-in-the",
      "authors": "ashpublications.org",
      "host": "ashpublications.org",
      "snippet": "Classic iron deficiency is characterized by a hypochromic, microcytic anemia, low absolute reticulocyte count, and ferritin <15 μg/L. Higher ferritin thresholds",
      "score": 0.39754128
    },
    {
      "number": 24,
      "title": "Scenario: Management of iron deficiency anaemia - CKS - NICE",
      "detail": "cks.nice.org.uk",
      "url": "https://cks.nice.org.uk/topics/anaemia-iron-deficiency/management/management",
      "authors": "cks.nice.org.uk",
      "host": "cks.nice.org.uk",
      "snippet": "Consider parenteral iron if oral iron is contraindicated, ineffective or not tolerated. Monitor the person to ensure that there is an adequate response to iron",
      "score": 0.66699636
    }
  ],
  "publishedAt": "2026-09-15T21:01:40.373152+00:00",
  "updatedAt": "2026-09-15T21:01:40.373152+00:00",
  "readingMinutes": 6,
  "slug": "iron-deficiency-anemia-gastrointestinal-evaluation"
}