0207 4781665

MBChB PhD FRCS

FAQs

Consultant Laparoscopic Colorectal and General Surgeon

Pre-surgery investigations

Colonoscopy – why would I need one?

Why expertise in colonoscopy is important

“Colonoscopy expertise is the key to a successful procedure and a more comfortable experience for the patient. A good colonoscopist does a lot of procedures, has a high success rate, a low complication rate and has a high proportion of patients who are able to tolerate the procedure with no sedation.”

Mr Jonathan Wilson has been trained in contemporary colonoscopy techniques at the Wolfson Unit for Endoscopy, St Mark’s Hospital, Harrow, which has an international reputation for excellence in colonoscopy. He is also a nationally accredited JAG (Joint Advisory Group on GI Endoscopy) endoscopist and performs colonoscopy regularly at The Whittington Health NHS Trust and The London Clinic.

A colonoscopy is an investigation of the large bowel. It is performed using a colonoscope, a long, flexible tube with a camera inside. It can also be used to introduce instruments into the colon to take samples if you need a biopsy or to remove polyps.

Hundreds of thousands of colonoscopies are done each year in the UK to investigate bowel problems.

Why a colonoscopy is useful

  • It is a good diagnostic tool – symptoms causing concern, such as rectal bleeding, abdominal pain and digestive problems, can be investigated by looking directly at the inside of the bowel.
  • A colonoscopy is a routine, day case procedure – you don’t need to stay in hospital overnight, and some patients don’t even need sedation.
  • It allows bowel cancer to be diagnosed early.
  • A colonoscopy allows diagnosis of inflammatory bowel disease (IBD).
  • It can rule out serious conditions, confirming a diagnosis of irritable bowel syndrome (IBS).
  • It can also be used to give treatment – polyps, small benign growths on the inner lining of the bowel, can be surgically removed during a colonoscopy.

Why might I need a colonoscopy?

  • If you have a change in your bowel habit.
  • If you experience rectal bleeding (not considered to be simply from haemorrhoids).
  • If you become anaemic for no obvious reason.
  • If you show unexplained weight loss or abdominal pain.
  • If you have a strong family history of colorectal cancer.
  • As ongoing surveillance if you have had previous polyp removal, bowel cancer surgery, or longstanding ulcerative colitis (IBD).
  • Concern from your GP for any other reason.

Preparing for colonoscopy

So that it’s possible to see your colon clearly, it is important that your bowel is completely empty. Normally it is full of food waste, so this needs to be cleared out in the 24 hours before your procedure. This means taking a very effective bowel cleansing preparation orally, which induces diarrhoea. Depending on the type of bowel preparation used in your hospital, the endoscopy staff will advise on the dietary dos and don’ts to follow the day before the test.

Colonoscopy: what happens?

Will I have sedation?

The majority of patients having a colonoscopy choose to have light intravenous sedation to make things more relaxing, although this is not essential. The sedation is not like a general anaesthetic, and you will be awake and asked to move around into different positions during the procedure.

During the colonoscopy a flexible tube that has an integral light and camera is passed through the anus and into the colon. Carbon dioxide gas is usually used to inflate your colon slightly, so that it is easier to manoeuvre the colonoscope and get a good view. It passes all the way along the large bowel, and your doctor will examine each portion of bowel carefully. The tube has a channel for instruments to allow removal of any polyps found, or sampling of any irregularities encountered.

The whole procedure takes about half an hour, perhaps a bit longer if you have a couple of polyps removed. Afterwards you will rest and doze if you have had sedation. Your abdomen may feel a bit bloated because of the carbon dioxide, but this will soon pass. As soon as you can get up and move around you can go home, but always arrange for someone to be with you, as you will not be allowed to drive yourself or use public transport alone.