The yield of colonoscopy in average-risk patients with non-specific colonic symptoms

Objectives The need for full colonoscopies in average-risk patients with non-specific colonic symptoms is controversial. We aimed to evaluate: (1) the yield of full colonoscopy; (2) the prevalence of proximal neoplasia in these patients; (3) the yield if any of doing full colonoscopies to diagnose proximal lesions in patients in whom the distal colon was clear; (4) the significance of this yield with respect to age. Design This is a retrospective analysis to assess the value of open access colonoscopy. Patients and methods All patients who underwent a colonoscopy in our Endoscopy Unit during January 1996 to December 1999 were assessed (n = 3357). Results We analysed 945 patients with average risk and non-specific colonic symptoms (significant risk factors excluded). The overall yield of adenomas was 5.8%. The yield of distal adenomas in patients greater than or equal to50 years of age was 8.2% (37 out of 450) versus 0.2% in the <50 years group (one out of 495; P = 0.0001). The proximal adenoma yield in ≥50 year olds was 3.8% (17 out of 495) versus 0.2% in <50 year olds (one out of 495) (P = 0.0001). Conclusions In a cohort of average-risk patients with nonspecific colonic symptoms attending an 'open access' colonoscopy clinic, the yield for proximal adenomas is small in the <50 years group. In patients aged <50 years, distal colonic examination is all that is required, whereas a full colonoscopy may be justified in patients greater than or equal to50 years old.