Are we doing too many surveillance colonoscopies on colonic adenoma? A 4-year study on a major colorectal cancer screening hospital

Introduction: The British Society of Gastroenterology (BSG) has set clear guidelines on post-polypectomy surveillance colonoscopy for adenomatous polyps. The present study aims to determine whether these guidelines were adhered to in a screening unit, where colonoscopy is offered to anyone between 50 and 69 with positive faecal occult blood testing. Methods: All patients (asymptomatic and symptomatic) who underwent surveillance colonoscopy were retrospectively included between 2003 and 2006. Surveillance colonoscopy was carried out as a follow-up examination to a patient previously found to have adenoma(s), malignancy, strong family history or history of inflammatory bowel disease. Patients with no evidence of adenomas on their baseline or any repeat colonoscopy were excluded. Information relating polyp number, size and histology was collected, and their subsequent schedule colonoscopy was then compared with the BSG guidelines. Results: Of the 1856 colonoscopies carried out, 779 cases of polyps were detected after exclusion criteria (478 symptomatic, 301 screened cases). In the symptomatic cohort, 344 cases (72%), whereas in the screened cohort, 242 cases (80%) were compliant with the BSG guidelines (P < 0.01). Reasons for non-compliance were premature follow up, late follow up, follow up occurring when not indicated, follow up not occurring when indicated, and the use of flexible sigmoidoscopy for follow up. Conclusion: Too many surveillance colonoscopies were performed in our unit. Targeting the reasons for non-compliance could potentially reduce workload and improve efficiency in an over-stretched colonoscopy unit.