Can I avoid a colonoscopy?
A colonoscopy is similar to an endoscopy, but the camera is inserted into the back passage (through the anus up into the rectum) to observe the large intestine (colon) and the lower part of the small intestine (ileum). As your colon can be up to 1.5 metres in length, the camera is long and flexible.
You will need to prepare your bowel for a colonoscopy by following a strict diet for two days before the procedure to ensure your colon is empty. This diet will involve eating only low fibre foods.
On the day before your procedure, you will need to take strong laxatives to help empty your bowel. Whilst taking these laxatives, you will normally drink plenty of water, and other clear liquids, such as apple juice, water and black tea or coffee. You will need to stay at home, with easy access to a toilet as you will have quite severe diarrhoea for some hours.
You may also be asked to stop taking certain medications in advance of your colonoscopy; these may include blood-thinning drugs such as clopidogrel or warfarin, to minimise any bleeding that may occur if biopsy samples are taken.
If you take any regular medicines, you should check with your doctor so that you know whether to continue or stop them before the test.
Most people choose to be sedated for colonoscopy. The sedation is not a full anaesthetic, but induces a very relaxed state, and in all likelihood will result in you having little or no memory of the procedure.
If you want to find out how people feel when they have a colonoscopy without sedation please feel free to read one person’s full account.
During the colonoscopy, your bowel is filled with air or, in the top endoscopy units, carbon dioxide to allow the camera to travel through more easily. This may make the procedure uncomfortable, but for most people this amounts to no more than mild discomfort. If the discomfort is worse, the sedation normally means that you have no real memory of this.
The doctor will observe your bowel and may take photographs or biopsy samples, depending on what is seen. Findings include
- Inflammation – seen in ulcerative colitis or Crohn’s disease
- Diverticula (pouches in the wall of the colon). Diverticular disease is present when there are multiple diverticula. These can become inflamed and cause pain. They can also cause scarring which leads to constipation or diarrhoea
- Polyps (pre-cancerous growths). Our doctors usually remove these during the same test so that you do not need to return later to have them taken out
- Rarely a cancer may be found.
- The doctor will use these observations to decide on a diagnosis/treatment plan for you, or may want to send you for further tests.
If you have sedation for your colonoscopy, you will be monitored for a short time after your procedure, and have someone with you for the next few hours. You will not be allowed to drive or operate heavy machinery for at least 24 hours, to ensure the effects of the sedative have fully worn off.
Please note that endoscopy and colonoscopy can, and often are, performed at the same time. This is generally easier for the patient than coming back twice!
Alternatives to colonoscopy
Various other tests might give similar information. These might make a colonoscopy unnecessary.
- Faecal calprotectin: this new stool sample test is a good way to exclude inflammation in the bowel. If it is negative, it is unlikely you have ulcerative colitis or Crohn’s disease
- Virtual colonoscopy (CT pneumocolon) This is a non-invasive way of looking for polyps or cancer in the bowel. It is not yet quite as good as colonoscopy although it continues to improve. If a polyp is found, you will still need to have a colonoscopy to remove it.
- Faecal occult blood testing: This test is the basis of the UK colon cancer screening programme. It is an excellent way of detecting people who do not have symptoms but might have early bowel cancer. The problem is that for a person with symptoms, a negative test is not good enough to exclude cancer. If you have symptoms, please do not rely on this test.
At the London Gastroenterology Centre, we have expert consultants who offer colonoscopies. Call our office on 020 7183 7965 to make an appointment.