Colonoscopy: What to Expect and Why It Could Save Your Life

Colonoscopy is an endoscopic procedure in which a flexible tube with a camera (colonoscope) is inserted through the rectum to visually inspect the entire large intestine (colon and rectum). It is the gold standard investigation for colorectal cancer screening, evaluation of rectal bleeding, change in bowel habits, abdominal pain, and investigation of conditions such as inflammatory bowel disease (IBD — Crohn's disease and ulcerative colitis), polyps, and diverticular disease.

In Korea, colonoscopy is performed at major hospital gastroenterology departments and numerous private gastroenterology clinics. The procedure is performed under conscious sedation (intravenous midazolam and/or propofol) — patients are relaxed and drowsy but usually not fully unconscious. A driver is required to take the patient home. The procedure itself takes 20–45 minutes, though the entire appointment including preparation and recovery takes 2–4 hours.

Bowel preparation (a laxative solution taken the day before) is the most important factor in colonoscopy quality — incomplete preparation prevents adequate visualisation. If polyps are found, they can be removed during the same procedure (polypectomy) — this is one of the most powerful aspects of colonoscopy, as removing pre-malignant polyps prevents colorectal cancer. Colorectal cancer screening colonoscopy is recommended at age 45–50 for average-risk individuals, or earlier for those with a family history or prior polyps.