Is it standard practice to take random biopsies from each part of the colon as part of a colonoscopy, even when no polyps are seen?

For colonoscopy screening for colon cancer, usually only polyps or similar abnormalities are biopsied. For inflammatory bowel disease diagnosis or management, there might be random samples in addition to biopsy of suspicious looking areas. Discuss with your colonoscopist.

It depends on the reason for the colonoscopy. If it is just a screening exam, routine biopsies are not needed. If it is being done for diagnosis of chronic diarrhea or the possibility of inflammatory bowel disease, routine biopsies throughout may be taken. You should discuss this with your G.I. doctor. Good luck.