A Large Comparative Cohort Study of Colonoscopy in the Elderly: Indications, Outcomes, and Technical Aspects.

Introduction  Performing colonoscopy in the elderly is associated with unique challenges, including higher rates of comorbidities, limited physiological reserve, and procedural complexities. This study aimed to evaluate the technical aspects, indications, and outcomes of colonoscopy in the elderly, with an emphasis on indication-based diagnostic yield. Methods  In this retrospective cohort study, we reviewed 35,000 consecutive colonoscopy procedures performed over a 12-year period on patients aged 50 years and older. Patients were categorized into three groups: very elderly (>80 years, n=3,434), elderly (65-80 years, n=13,783), and younger controls (50-64 years, n=17,959). Clinical and endoscopic findings were analyzed, with a focus on indication-specific outcomes. Results  The most frequent indications for colonoscopy in the very elderly and elderly groups were anemia and rectal bleeding. Both elderly groups exhibited higher rates of inpatient procedures (49.2% and 20.9% vs. 9.6%; P<0.0001), inadequate bowel preparation (18.5% and 13.5% vs. 9.1%; P<0.0001), and anesthesiologist involvement in sedation (6.0% and 3.9% vs. 2.1%; P=0.03) but required lower doses of propofol sedation (4.5% and 5.4% vs. 7.9%; P=0.026). Colorectal cancer (CRC), polyps, and diverticulosis detection increased linearly with age. Colonoscopies performed for anemia or rectal bleeding yielded higher CRC and polyp detection rates, whereas constipation was associated with the lowest diagnostic yield. Conclusion This study highlights the technical challenges associated with performing colonoscopy in elderly patients, identifies indications with the highest diagnostic yield, and underscores the necessity of tailored bowel preparation protocols and an indication-driven approach to optimize the clinical utility of colonoscopy in this population.