Yield of adenomas and colorectal cancers within 5 years of a negative colonoscopy: are the guidelines guiding?

Background Screening for colorectal cancers outside the recommended guidelines presents a considerable burden to resource management in many public hospitals. The aim of this study is to evaluate the frequency, indications and outcomes for repeat colonoscopy performed within 5 years of a negative colonoscopy. Methods A retrospective review of all colonoscopies at Nambour Hospital in 2008 was performed to identify those with a negative colonoscopy. The charts of patients undergoing repeat colonoscopy at the same institution within 5 years of a negative colonoscopy were examined further, and data obtained regarding indications and outcomes of subsequent colonoscopies. Results A total of 616 colonoscopies were identified, 427 (69.3%) were negative for adenoma and carcinoma. Of these patients, 74 (17.3%) underwent a repeat colonoscopy at Nambour Hospital within 5 years. Eighteen out of 74 (24.3%) were outside guideline recommendation. Overall, one patient (1.4%) had cancer and 11 patients (14.9%) had polyps detected at repeat colonoscopy. Most of the polyps detected had low‐risk features and were detected in the fourth and fifth years of the study period. Conclusion The yield of a second colonoscopy within 5 years of a good‐quality negative colonoscopy is low but not zero. In the absence of new concerning symptoms or other risk factors, patients can be reassured and guidelines adhered to.