Background and study aims: Guidelines and practices differ regarding evaluation of young patients with fresh bleeding per rectum (FBPR). The aim of this study was to determine the frequency and site of endoscopic lesions in young patients with FBPR, and to thereby determine whether full colonoscopic examination is necessary in these patients. Methods: Consecutive patients aged 1850 years who were scheduled to undergo full colonoscopy for FBPR at Aga Khan University Hospital between May 2007 and October 2009 were enrolled in the study after giving informed consent. FBPR was defined as the passing of fresh blood per rectum with or without stools and/or noticing blood in the toilet bowl. Lesions were characterized as proximal or distal to the splenic flexure. Patients with positive family history of colorectal cancer, bleeding requiring blood transfusion, bleeding diathesis, or iron deficiency anemia were excluded. Results: A total of 379 patients met the inclusion criteria and were analyzed. Of these, 248 patients (65.4%) were under 40 years of age and 131 (34.6%) were aged 4050 years. Mean hemoglobin was 12.931.78g/dL. In patients <40 years, seven (2.8%) adenomatous polyps and malignant lesions were found, all of which were located in the distal colon. In patients aged 4050 years, 10 (7.6%) adenomatous polyps and malignant lesions were detected, one of which was located in the proximal colon. On univariate analysis, malignant and adenomatous lesions were significant in the 4050 years age group (P=0.031; OR, 2.84; 95%CI 1.057.65). Conclusion: Endoscopic lesions in patients younger than 40 years with FBPR are found mostly in the distal colon and hence flexible sigmoidoscopy seems to be a reasonable evaluation tool in young patients with no other alarm symptoms.