['General practitioners (GPs) in the Netherlands have open access to flexible sigmoidoscopy (FS) for patients with lower gastrointestinal symptoms, but not to colonoscopy. This study was performed to investigate the yield of FS in GP-referred patients, to evaluate the proportion of patients in whom additional colonoscopy was performed and to investigate whether there was a subgroup of patients referred for symptoms with a low risk of detecting significant findings.', 'All patients undergoing FS in 2008 and 2009 who were referred by GPs were analyzed. Indications for additional colonoscopy were the presence of polyps and/or colorectal cancer (CRC), polyp screening or surveillance, incomplete FS or other reasons.', 'In total, 916 patients underwent FS. A cause for the symptoms was found in 44.2% of patients. In patients aged 50 years or older, additional colonoscopy was more frequently performed than in younger patients (27.5% vs. 9.6%, OR=3.6 [95% CI 2.4-5.4]), mainly due to a higher prevalence of adenomatous polyps (29.9% vs. 10.5%, OR=3.6 [95% CI 2.4-5.4]) and CRC (7.5% vs. 1.3%, OR=6.2 [95% CI 2.2-17.5]) during FS. In 7.8% patients undergoing FS for abdominal pain as the presenting symptom, a probable cause for the symptoms was found, mainly diverticular disease.'] Does open-access flexible sigmoidoscopy frequently lead to additional colonoscopy in symptomatic patients over 50 years?