Bowel: FIT and colonoscopy, who needs what

Bowel testing comes down to two tools that do different jobs: the FIT test and the colonoscopy.

FIT is a home test. You collect a tiny stool sample and post it, and the lab looks for traces of blood too small to see. It is simple, it is the same test the NHS uses, and it is a good first filter. The NHS sends a FIT kit free to everyone aged 50 to 74 in England every two years, and from 2026 it reads at a more sensitive threshold, so if you are in that band and a kit arrives, use it.

Colonoscopy is the camera. A thin flexible scope looks directly at the lining of the bowel, and its advantage is that it both sees and treats: a polyp found can usually be removed in the same procedure, before it ever has the chance to become a cancer. It is the right test where there are symptoms, where a FIT is positive, or where your risk is high enough to start with it.

There is also CT colonography, a scan that maps the bowel, used when a colonoscopy is not feasible. Its limit is that anything it finds still needs a colonoscopy to deal with, so it is a second choice rather than a first.

With us, you can do a FIT if you fall outside the NHS age band, or want one between NHS rounds, and where a colonoscopy is warranted we arrange it privately, or give you a letter to take to your GP. A normal FIT is reassuring rather than absolute, so if you have symptoms that worry you, that is a reason to look regardless of the result, and we will say so.

Ready to start? Choose the check that fits your question and tell us a little about yourself. A doctor reviews it, arranges what you need, and explains what it means. Most of it is done online, with the clinic there if you would rather be seen.