Endoscopy
Examination of the inside of the body using a flexible tube with a camera.
What it means
Endoscopy is direct visual examination inside the body using a flexible tube carrying a camera and light. From the Greek endon, within, and skopein, to look.
Named by what is examined:
- Gastroscopy (or OGD) — oesophagus, stomach and duodenum, via the mouth
- Colonoscopy — the whole large bowel, via the rectum
- Flexible sigmoidoscopy — the lower large bowel only
- Cystoscopy — the bladder
- Bronchoscopy — the airways
The advantage over a scan is that endoscopy both looks and acts — taking biopsies, removing polyps, stopping bleeding and stretching narrowings in the same session.
In practice
Usually performed with a local anaesthetic throat spray, light sedation, or both. Sedation means someone must accompany the patient home and no driving for 24 hours.
Reports describe findings by distance from a landmark, and note any biopsies taken.
Why it matters
Endoscopy is the appropriate investigation for persistent difficulty swallowing, persistent indigestion in older adults, unexplained iron deficiency anaemia, and a change in bowel habit with bleeding.
These are situations where we would refer rather than treat remotely, however clear the story sounds — acid-suppressing medication can mask a cancer while it grows.
Clinically reviewed by Dr Mohammad Zubair Khan, GMC 7563469
Last reviewed
August 30, 2026