Flexible sigmoidoscopy as the preferred initial investigation for patients with low-risk colorectal symptoms requires formal evaluation. From August 1999 to July 2001, 323 patients (166 men) attended the one-stop colorectal clinic. All the patients were examined using a 60-cm flexible sigmoidoscope. Presenting symptoms and findings were reviewed. The mean age of the study patients was 38.6 +/- 11.87 years, with the majority (89.1%) younger than 50 years. Rectal bleeding was the most common problem (86.6%), followed by bowel habit change (13.7%). For 65.6% of the patients, a view to the proximal sigmoid was obtained. The main reason for incomplete assessment was poor bowel preparation (67.5%). The most common finding, in 202 patients (64%), was haemorrhoids. Polyps were found in 9.9% of the patients, whereas four patients (1.2%) with cancer were identified. Overall, 269 patients (83.4%) required no further investigation. Flexible sigmoidoscopy is an effective method for assessing low-risk patients.