“Is a colonoscopy safe?”

Yes, it is a very routine and relatively safe procedure. Based on large studies, the risk of any complication is < 1/1000. Risk of perforation is less than 1/3000.

Colonoscopy is generally quite safe and well tolerated. Most people over 50 have had one. Risks of the procedure include bleeding and perforation. Your risk of this depends on many factors, such as if you use blood thinner medications and if the doctor needs to cut out pre-cancerous polyps during the procedure. So if you have polyps, the risk is higher. But then again, failure to remove the polyps could lead to colon cancer. You pick your risks. Complications are rare of course. Then again, you assume risk simply by getting in the car to drive to your procedure!