Repeated Fecal Occult Blood Test Positivity Is Associated with Clinically Significant Colonoscopic Findings
Objective: Guaiac-based fecal occult blood testing (gFOBT) is widely used in colorectal cancer (CRC) screening programs. To evaluate the association between repeated gFOBT positivity and clinically significant colonoscopic and histopathological findings, particularly colorectal malignancy.
Methods: This retrospective, single-center study included patients with positive gFOBT results who presented to the Gastroenterology Outpatient Clinic of Gazi University Faculty of Medicine between June 2017 and October 2025. Patients were categorized into three groups based on gFOBT results: single positive (Group 1), two consecutive positive tests within one month (Group 2), and an initial positive followed by a negative test (Group 3). Colonoscopic and histopathological findings were compared between groups. Multivariable logistic regression analysis was performed to identify independent predictors of clinically significant malignant pathology.
Results: Among 1,442 patients with positive gFOBT results, 735 (50.9%) underwent diagnostic colonoscopy. Colorectal malignancy was detected in 55 (7.5%) patients among those who underwent colonoscopy. Malignancy rates differed significantly between groups: 5.1% in Group 1, 17.4% in Group 2, and 0% in Group 3 (P<0.001). Repeated gFOBT positivity was independently associated with malignant colonoscopic findings (OR: 3.684; 95% CI: 2.027–6.694). Normal colonoscopy findings were significantly more frequent in patients with a single positive test, whereas malignant findings were markedly higher in patients with repeated positivity.
Conclusion: Repeated gFOBT positivity is strongly associated with clinically significant colonoscopic pathology, particularly colorectal malignancy. Patients with consecutive positive gFOBT results represent a high-risk subgroup and should be prioritized for prompt diagnostic colonoscopy within CRC screening programs.
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Article Information
- Article Type Research Article
- Submitted April 13, 2026
- Accepted June 10, 2026
- Published June 15, 2026
- Issue 2026: Online First
- Section Research Article
- Categories
All data generated or analyzed during this study are included in this published article. The data that support the findings of this study are available on request from the corresponding author, upon reasonable request.
