Rectal bleeding is a common reason for consultation, with etiologies ranging from benign anorectal and colorectal conditions to more severe diseases, including neoplastic processes, whose prevalence varies with age.The aim of this study was to assess the diagnostic value of colonoscopy in cases of rectal bleeding according to patient age.

A retrospective descriptive and analytical study was conducted from January 2022 to December 2024, including 225 patients who underwent colonoscopy for rectal bleeding. Patients were divided into two groups: Group 1 (patients under 50 years) and Group 2 (patients over 50 years). Epidemiological, clinical, and endoscopic data were compared between the two groups.Patients diagnosed with inflammatory bowel disease (IBD) were excluded. Statistical analysis was performed using Jamovi software version 2.3.28.

Results:

The mean age of patients was 54 ± 13 years, with a female predominance: 120 women (53.3%) and 105 men (46.6%), corresponding to a male-to-female ratio of 0.9.Among the 225 patients presenting with rectal bleeding, 35.6% were under 50 years of age and 64.4% were over 50. Rectal bleeding was isolated in 50.5% of cases, associated with constipation in 20.3% (G1: 15% vs G2: 13%; p = 0.213), with diarrhea in 17.3% (G1: 13% vs G2: 9.9%; p = 0.184), and with iron-deficiency anemia in 8% (G1: 6.8% vs G2: 6.7%; p = 0.645).Colonoscopy findings were normal in 57% of cases and pathological in 43% (G1: 30.6% vs G2: 69.3%; p = 0.001).The most frequently observed pathologies were: colorectal polyps in 46.6% of cases (G1: 30.7% vs G2: 52.1%; p = 0.041) , rectitis/colitis in 23.2% (G1: 46.6% vs G2: 10.9%; p < 0.002) , colorectal tumors or suspicious processes in 14% (G1: 6.7% vs G2: 19.7%; p = 0.02)  colonic diverticulosis in 11% (G1: 6.3% vs G2: 12.8%; p = 0.122) , colonic angiodysplasia in 8% (G1: 5.2% vs G2: 13.5%; p = 0.409) , solitary rectal ulcer in 1.3% (G1: 0.8% vs G2: 0.4%; p = 0.816). Univariate and multivariate analyses revealed that factors associated with pathological colonoscopy findings in rectal bleeding were age over 50 years (p = 0.03) and the presence of associated constipation (p = 0.011).

Colonoscopy remains a key diagnostic tool in the evaluation of rectal bleeding. In our study, age over 50 years was associated with pathological findings, most commonly polyps and colorectal lesions, whereas rectitis or rectocolitis was the most frequent diagnosis in patients under 50 years.