A colonoscopy is a way of examining the inside of your entire large bowel (the last part of your digestive system that consists of your bowel and rectum).
The examination is carried out using a long, thin flexible tube that has a camera and light source on one end, called an endoscope. Images of the inside of your body are sent to a television screen for your doctor to see. An endoscope is inserted into your body through a natural opening of your mouth or bottom so you don’t need any cuts.
A colonoscopy can see any irritated tissue or growths in your large bowel. It is the most effective way to diagnose bowel cancer.
A colonoscopy may be offered as part of the national bowel cancer screening programme. It may be recommended to investigate bowel symptoms that you are experiencing.
A colonoscopy is used to find out if you have a problem with your large bowel. This can include aggravated and swollen tissue, ulcers, growths such as polyps, or cancerous cells. During a colonoscopy your doctor may take a small sample of cells, known as a biopsy, or remove a polyp. It can help diagnose conditions including: Crohn’s disease, ulcerative colitis, diverticular disease and bowel cancer.
Typically, a colonoscopy is used to see inside your large bowel, but it isn’t appropriate for everyone.
Alternative tests include:
A colonoscopy usually takes around 45 minutes to perform. You may be offered a sedative or painkiller.
Your doctor will gently insert the colonoscope into your back passage. Air will be pumped into your large bowel to inflate it and give a clear view. The colonoscope will be passed through your bowel and your doctor will see images of it on a monitor.
A small sample of cells (biopsy) may be taken from your bowel and sent to a laboratory for testing to check if they are benign (non-cancerous) or malignant (cancerous).
If polyps are detected, they will probably be removed to reduce your risk of bowel cancer developing. Polyps are small growths on the lining of your bowel that are usually benign but some may develop into cancer over time. They are simply removed using tiny instruments that are passed through the colonoscope.
If you had a sedative, you will need to rest for an hour or two until its effects have passed. You will need to arrange a lift home.
Your doctor may talk to you about some findings from the colonoscopy before you leave, or they may arrange a follow-up appointment. If they have taken a biopsy or removed polyps, your results will be sent to your referring doctor.
You should be able to return to work the day after the colonoscopy.
A colonoscopy performed for bowel cancer screening can detect bowel cancer at its earliest stage, when there is the highest chance of curing it. It can also prevent some bowel cancers from developing.
A colonoscope will help diagnose your bowel symptoms so that an appropriate treatment plan can be developed for you. If a polyp is detected it can be removed whilst benign.
Complications of a colonoscopy may include: