Colonoscopy
What is a Colonoscopy?
A colonoscopy is a test that allows a consultant to look at the inner lining of your large intestine (rectum and colon). We use a thin, flexible tube called a colonoscope to look at the colon.


Figure 1 – colonoscopy
What are the benefits of a colonoscopy?
A colonoscopy helps identify conditions such as:
- ulcers
- colon polyps
- tumours
- areas of inflammation.
Is a colonoscopy right for me?
A colonoscopy can help to explore possible causes of:
- abdominal pain
- rectal bleeding
- chronic constipation
- chronic diarrhoea
- other intestinal problems.
If you’re over 50 your doctor may recommend a colonoscopy every 10 years, or sometimes sooner, to screen for colon cancer. Even if you have no other risk factors, age can increase your risk of getting colon cancer.
If you’ve had polyps before, a follow-up colonoscopy can find and remove any additional polyps. This is done to reduce your risk of colon cancer.
What happens during a colonoscopy?
Preparing for a colonoscopy
Before a colonoscopy, you’ll need to clean out (empty) your colon. If your colon lining isn’t clear of solids or liquids, then the colonoscope may not have a clear view of the rectum.
2 days before your colonoscopy – eat a low-fibre diet to help keep your colon clear.
The day before your colonoscopy – your doctor will ask you to drink laxative sachets to empty your bowels. You’ll probably get diarrhoea a few hours after taking the first sachet, so it’s best to be at home all day so that you’re close to a toilet.
The day of your colonoscopy – you’ll take the last dose of the laxatives before coming to the hospital. It is endorsed by the British Society of Gastroenterology to start the last dose of bowel preparation within 5 hours of colonoscopy as this improves bowel cleansing results. You may continue to drink until 2 hours before your procedure time.
During a colonoscopy
If appropriate, the endoscopist may offer you a sedative or painkiller. The procedure involves placing a flexible telescope into the back passage and blowing some air into the large bowel to get a clear view.
The endoscopist will be able to look for problems such as inflammation or polyps. They will also be able to perform biopsies and take photographs to help make a diagnosis.
A colonoscopy usually takes 30-45 minutes.
Is the procedure painful?
You may feel the camera going in, but it shouldn’t be painful. You may also experience bloating or stomach cramps, which are normal reactions. You may be given sedatives, painkillers or gas and air before your colonoscopy to help you feel more comfortable.
Recovery after a colonoscopy
If you were given a sedative, you will normally recover in about two hours. You should not drive for 24 hours and so you should arrange for somebody to take you home. You should also not drink alcohol or sign any legal documents for 24 hours.
You may feel a bit bloated for a few hours but this will pass
You should be able to go back to work the day after the colonoscopy.
If you did not have a sedative, you can go home and do everything as normal.
Are there any potential complications?
Although unlikely, there is a risk of certain complications, including:
- Damage to the colon
- Bleeding
- Vision going blurry
- Infection
- Not completing the procedure sufficiently
- Irregularities of the heart
- Breathing problems
Colonoscopy Information leaflets:
Colonoscopy
Gastroscopy with Colonoscopy
Use of Entonox
Colonoscopy aftercare advice
Gastroscopy with Colonoscopy aftercare advice
Therapeutic procedures offered: Polypectomy, Endoscopic Mucosal Resection, Banding of haemorrhoids, Argon Plasma Coagulation, Dye Spray, Dilatation, Insertion of metal stent and Botox injection.
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Qualifications
BSc MD FRCS
Clinical Interests
General surgery. Laparoscopic surgery. Colorectal surgery, colonoscopy and endoscopy. Minor operations.
Qualifications
BSc MD FRCS
Clinical Interests
General surgery. Laparoscopic surgery. Colorectal surgery, colonoscopy and endoscopy. Minor operations.
Qualifications
MD FRCS(Ed)
Clinical Interests
General surgery, colorectal surgery and laparoscopic surgery
Qualifications
MD FRCS(Ed)
Clinical Interests
General surgery, colorectal surgery and laparoscopic surgery
Qualifications
MB ChB MS(Lon) FRCS(Eng) FRCS(Gen Surg)
Clinical Interests
Bowel cancer, hernia surgery, gallstones, colonoscopy, haemorrhoids, anal fistula and fissures, and complex pilonidal...
Qualifications
MB ChB MS(Lon) FRCS(Eng) FRCS(Gen Surg)
Clinical Interests
Bowel cancer, hernia surgery, gallstones, colonoscopy, haemorrhoids, anal fistula and fissures, and complex pilonidal...
Clinical Interests
Colorectal surgery, including haemorrhoids and rectal prolapse. Endocrine conditions, including thyroid disorders, goitres,...
Clinical Interests
Colorectal surgery, including haemorrhoids and rectal prolapse. Endocrine conditions, including thyroid disorders, goitres,...
Qualifications
MBBS MS (Gen Surgery) FRCS
Clinical Interests
Hernia Surgery – Open & Laparoscopic
Gallstone / Gallbladder surgery
Rectal Bleeding
Treatment of haemorrhoids...
Qualifications
MBBS MS (Gen Surgery) FRCS
Clinical Interests
Hernia Surgery – Open & Laparoscopic
Gallstone / Gallbladder surgery
Rectal Bleeding
Treatment of haemorrhoids...
Qualifications
MS FRCS (Gen Surg)
Clinical Interests
Investigation and treatment of lower gastrointestinal disorders including:
Bowel cancer
Bowel polyps
Inflammatory disorders...
Qualifications
MS FRCS (Gen Surg)
Clinical Interests
Investigation and treatment of lower gastrointestinal disorders including:
Bowel cancer
Bowel polyps
Inflammatory disorders...
Qualifications
MBBS (Lond) MRCP (UK) FRCP FEBGH PhD (UCL)
Clinical Interests
Minimally-invasive Testing
Advanced Endoscopy including OGD, Colonoscopy, ERCP, Removal of Polyps, Enteral Stenting,...
Qualifications
MBBS (Lond) MRCP (UK) FRCP FEBGH PhD (UCL)
Clinical Interests
Minimally-invasive Testing
Advanced Endoscopy including OGD, Colonoscopy, ERCP, Removal of Polyps, Enteral Stenting,...
Qualifications
MA MB BChir MRCP PhD
Clinical Interests
Abdominal pain
Acid reflux
Bleeding
Bowel cancer screening
Bowel problems
Constipation
Diarrhoea
Endoscopy (specialist...
Qualifications
MA MB BChir MRCP PhD
Clinical Interests
Abdominal pain
Acid reflux
Bleeding
Bowel cancer screening
Bowel problems
Constipation
Diarrhoea
Endoscopy (specialist...
Qualifications
BSc MBBS FRCP
Clinical Interests
Colorectal cancer screening and surveillance, dyspepsia, Crohns disease and ulceractive colitis, liver and pancreatobiliary...
Qualifications
BSc MBBS FRCP
Clinical Interests
Colorectal cancer screening and surveillance, dyspepsia, Crohns disease and ulceractive colitis, liver and pancreatobiliary...
Qualifications
MD FRCP PhD(Edin) FACG
Clinical Interests
Inflammatory Bowel Disease and nutrition. Dyspepsia and fatty liver.
Qualifications
MD FRCP PhD(Edin) FACG
Clinical Interests
Inflammatory Bowel Disease and nutrition. Dyspepsia and fatty liver.
Clinical Interests
Diagnostic and therapeutic endoscopy, colonoscopy and ERCP. Inflammatory bowel disease, irritable bowel syndrome and...
Clinical Interests
Diagnostic and therapeutic endoscopy, colonoscopy and ERCP. Inflammatory bowel disease, irritable bowel syndrome and...