Colonoscopic findings and diagnostic yield in young adults with lower gastrointestinal bleeding in Saudi Arabia: a multicenter retrospective study

Lower gastrointestinal bleeding (LGIB) in young adults is often attributed to benign anorectal conditions; however, clinically significant pathology may occur. Data on colonoscopic findings and associated factors among young adults in Saudi Arabia remain limited. This study evaluated colonoscopic findings and factors independently associated with abnormal colonoscopy in adults aged 18–50 years presenting with LGIB. This multicenter retrospective cohort study included patients from eight Saudi hospitals between January 2020 and December 2025. Demographic characteristics, comorbidities, medication use, family history, colonoscopy findings, and clinical outcomes were extracted from electronic medical records. Associations with abnormal colonoscopy findings were assessed using univariable analyses and multivariable logistic regression, with adjusted odds ratios (aORs) and 95% confidence intervals (CIs) reported. Among 993 patients with evaluable colonoscopy findings, the median age was 36 years (IQR 28–42), and 59.9% were male. Abnormal findings occurred in 601 patients (60.5%). Inflammation/ulceration was identified in 37.3%, polyp/mass/cancer in 17.2%, IBD-related findings in 4.7%, and diverticulosis in 1.3%. In multivariable analysis, family history of IBD (aOR 3.18, 95% CI 1.05–9.68; p = 0.042) and anticoagulant use (aOR 3.34, 95% CI 1.60–6.99; p = 0.001) were independently associated with higher odds of abnormal findings. GERD was associated with lower odds (aOR 0.49, 95% CI 0.32–0.74; p = 0.001). Abnormal colonoscopic findings were common among young adults with LGIB. Family history of IBD and anticoagulant use were independently associated with abnormal findings, warranting prospective validation.