If you have Irritable Bowel Syndrome, you may need a colonoscopy procedure. I will take you through the preparation, you can view endoscopic pictures and see a demonstration video on this page.
A colonoscopy is commonly performed test in people with IBS particularly if there are any unusual symptoms such as rectal bleeding.
The examination should be normal, but when intestinal symptoms are present, other conditions such as colon cancer, polyps and inflammatory bowel disease need to be excluded.
The procedure is performed by a colonoscopist trained in the technique of passing a camera or colonoscope into the colon.
The colonoscope is passed as far as the cecum or terminal ileum (end bit of your small intestine).
They can see pictures on a monitor or TV screen transmitted from the colonoscope.
You can view a colonoscopy video at the American society for Gastrointestinal Endoscopy - a link can be found on this page.
Colonoscopy preparation involves taking a laxative or 'preparation' to clear the colon out.
The procedure is unlikely to be completed if the prep isn't good enough as visualization of the intestine won't be achieved.
The choice of bowel preparation for your colonoscopy procedure varies from one hospital to another, so you will need to seek guidance locally.
When you enter the endoscopy room you will have a needle placed in your hand through which a sedative will be given.
You will be asked to lie on your left hand side and have oxygen administered to you through a nasal cannula (tube close to your nostrils).
The colonoscopist or gastroenterologist will do a PR or 'per rectal' examination by passing their right index finger through your anus or ‘back passage’ into your rectum or lowest part of your colon.
They can feel for lumps and also check the prostate gland in a male.
It is a good way of defining the quality of your bowel preparation as well as checking for blood and assessing the strength of your anus muscles.
The colonoscope is then passed through the anus into the rectum and air or carbon dioxide is used to inflate the intestine.
During your colonoscopy procedure the colonoscopist will pass the camera around your intestine to the first part of the colon called the cecum. This is where your small intestine connects to the large bowel.
The colonoscope can be pushed through into the small bowel, but this can be technically difficult sometimes. If achieved it is called an Ileocolonoscopy.
During the colonoscopy procedure, pieces of tissue or biopsies can be taken to analyze in the laboratory.
Sometimes polyps (a cherry-like protuberance in the bowel) can be removed too. In IBS, the results of biopsies should be normal.
To do this, biopsy forceps are passed through the colonoscope or a snare if polyps are present.
To remove polyps, a current is passed through the snare wire to cut the polyp off through burning or 'cauterizing'.
To do this a pad to complete the electric circuit (an earth) will be placed, usually on your thigh first to make this procedure as safe as possible for you.
Colonoscopy is usually done as an outpatient or day case and involves sedation.
This is usually with a drug called a benzodiazepine plus a strong pain killer.
The main ones given are Pethidine or Fentanyl, as the test can sometimes be uncomfortable (particularly in people with IBS due to the increased sensitivity of the bowel).
The drugs are usually given by an injection into a vein on the back of your hand.
The sedative makes you drowsy but it does not 'put you to sleep' (i.e. It is not a general anesthetic). In some centers, Propafol anesthetic is administered.
The test normally takes 20-30 minutes to perform, but you will feel the effects of the sedation for up to 24 hours.
During this time you can’t drive, operate machinery or sign any legal documents.
You should be accompanied on the day of your test and may feel a bit ‘gassy’ from the air that has been put in your bowel post-procedure, but this normally settles fairly quickly.
Fortunately, complications are rare.
The main colonoscopy procedure risks are perforation or putting a ‘hole’ in the bowel during the test.
This can make you quite sick, give you a fever and worsening abdominal pain. If this occurs, it would normally need repairing by an operation.
Other complications include bleeding (although rarely requires a blood transfusion) and reaction to the sedation.
This is normally monitored closely during your investigation by an assistant or endoscopy nurse who will be taking regular observations (pulse, blood pressure and oxygen levels during the test).
This procedure is a common investigation in determining the cause of your bowel symptoms such as IBS, IBD and early colon cancer.
An alternative way of visualizing the colon is through the use of a barium enema or CT scan for those not fit enough for a colonoscopy procedure.