S1226 A Swallow Away From the Source: Diagnostic Insights From Capsule Endoscopy in Iron Deficiency Anemia

Introduction: Iron deficiency anemia (IDA) is a common nutritional deficiency and a significant cause of morbidity. When initial evaluation with esophagogastroduodenoscopy (EGD) and colonoscopy fails to identify a gastrointestinal (GI) bleeding source, video capsule endoscopy (VCE) offers a non-invasive method to visualize the small intestine, a region inaccessible by standard endoscopy. VCE is effective in detecting lesions such as angiodysplasias, ulcers, and tumors. This study examines the diagnostic yield, lesion characteristics, and subsequent management in patients with IDA who underwent VCE after negative EGD and colonoscopy. Methods: A retrospective case-control study was conducted on 157 patients with IDA who underwent VCE between January 2020 and December 2024 following negative bidirectional endoscopy. Clinical data included demographics, comorbidities, medications, labs, transfusion history, and VCE findings. Patients were stratified by VCE result (positive vs negative), and downstream management was assessed. Results: Of 157 patients, 95 (60.5%) had positive VCE findings. The mean age was 69.4 years; 58% were female. Common comorbidities included hypertension (80%), cardiovascular disease (73%), and diabetes (46%). Mean hemoglobin was 8.2 g/dL; ferritin 22.2 ng/mL; iron 30.7 µg/dL. Patients were frequently on nonsteroidal anti-inflammatory drugs (55%), proton pump inhibitors (76%), and antithrombotic agents (52%). Most patients (81%) had prior blood transfusions (mean 6.7 units), and 43% received iron infusions. VCE most frequently revealed arteriovenous malformations (41%), active bleeding (23%), and inflammatory lesions (15%), often in the proximal small bowel (41%). Follow-up endoscopy, typically push enteroscopy, was performed in 54% of patients. Comparing positive and negative VCE groups, there were no significant differences in baseline demographics, comorbidities, medication use, or labs. However, positive cases were associated with higher rates of follow-up endoscopy (54% vs 11%, P < 0.001) and less observation-only management (15% vs 56%, P < 0.001). Positive cases also trended toward greater transfusion needs (mean 6.7 vs 3.6 units, P = 0.06). No adverse events were reported. Conclusion: VCE demonstrates a meaningful diagnostic yield in patients with iron deficiency anemia and non-diagnostic EGD/colonoscopy. Findings often reveal actionable lesions and guide management. These results support integrating VCE into diagnostic algorithms for unexplained IDA.