I’m up in age. My doctor recommends one every 5 years.
I had last one in May. I’m in “high risk” category, ie my dad had colon cancer. Doc wants another in 5 years when I’m 85. He’s always found a crop of polyps in me.
From my reading colonoscopies cause more damage than they find. In my book there should be a symptom which would point at the need for a colonoscopy before submitting to one. I think a large swath of non-proctologists think the same way. Proctologists get paid for colonoscopies. Of course they recommend them ....daily.