A colonoscopy is a method of examining the lining of the bowel from the inside, allowing your consultant to look into your colon. The colon is sometimes called the large intestine or large bowel.
A colonoscope is a thin, flexible telescope. It is about as thick as your little finger. It is passed through the anus and into the colon. It may be pushed all the way round the colon as far as the caecum. The colonoscope contains fibre-optic channels that allow light to shine down, so that your doctor can see inside your colon. The colonoscope also has a channel down its side, through which devices can pass and be manipulated by your doctor to take a small sample, in the form of a biopsy, from the inside lining of the colon.
A colonoscopy may be advised if you have symptoms such as bleeding from the anus, pains in the lower abdomen or persistent diarrhoea. It may be used to confirm or exclude conditions, such as ulcerative colitis, Crohn’s disease, diverticulitis, the presence of polyps and cancer.
Colonoscopy is usually performed as an outpatient or day case. You will usually be given a sedative to help you to relax. The sedative can make you drowsy but does not put you to sleep. It is not a general anaesthetic. You will need to lie on your side on a treatment couch. Your consultant will gently push the end of the colonoscope into your anus and up into the colon. Your doctor can look into the colonoscope and inspect the lining of the colon.
Baddow Hospital uses colonoscopies which transmit pictures through a camera attachment on to a monitor for the doctor to look at. Air is passed down a channel in the colonoscope into the colon to make the inside lining easier to see. This may cause you to feel as though you want to defecate. The air may also make you feel bloated, cause some mild wind pains, and may cause you to pass wind. Your doctor may take biopsies of some parts of the inside lining of the colon. It is possible to remove polyps, with an instrument attached to a colonoscope. At the end of the procedure the colonoscope is gently pulled out.
A colonoscopy usually takes about 20-30 minutes. However, you should allow at least two hours for the whole appointment to prepare, give time for the sedative to work, for the colonoscopy itself, and to recover. A colonoscopy does not usually hurt, but it can be a little uncomfortable.
Your consultant will provide instructions prior to your investigations, including:
- The requirement to follow a special diet for a few days before the test. It’s necessary to strictly observe your consultant’s dietary advice, which may consist of a very light diet for 1-2 days prior to the procedure and clear fluids for the morning prior to an afternoon procedure.
- You will also be given some laxatives/bowel-cleansing agents to take in advance.
Most people are ready to go home after resting for half an hour or so. You may need to stay a bit longer for observation if you have had a biopsy or had polyps removed.
If you had a sedative you may take a little longer to recover, and will need somebody to accompany you home and stay with you for 24 hours until the effects have fully worn off, as you will be drowsy.
You should not drive, operate machinery, drink alcohol, take important decisions or sign documents for 24 hours after having a sedative. Most people are able to resume normal activities after this period.
For most people a colonoscopy is a straightforward procedure and they will have no side effects. Rarely however, complications may occur, including:
- Fluid loss
- Breathing problems
- Heavy bleeding from your rectum
If you are concerned about any post-treatment symptoms, please contact the hospital immediately.