Gastroenterology• Updated 21 October 2026
Colonoscopy
A procedure using a thin camera to look inside the large bowel and remove polyps.
Results: Same day; biopsies in a few days
Quick Summary
Primary Purpose
To investigate bleeding, bowel changes, anaemia and screen for bowel cancer.
What It Measures
The lining of the colon and rectum, with biopsies and polyp removal.
Preparation
Special diet and strong laxatives the day before to empty the bowel.
Overview
Good bowel preparation is essential for a clear view.
Removing polyps prevents bowel cancer.
What It Measures
Lining
Inflammation, polyps, cancer.
Biopsies
Tissue samples.
How It's Performed
- 01
Bowel prep
Laxatives the day before.
- 02
Procedure
Camera through the bottom with sedation, 20–45 minutes.
- 03
Recovery
Wind and bloating are common.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Colonoscopy(opens in a new tab) · MedlinePlus, US National Library of Medicine
- Colonoscopy(opens in a new tab) · NHS