A colonoscopy is a camera test, used to take a direct look at the inside of your rectum and large intestine.
The instrument used to perform colonoscopy is called a colonoscope. It is a long flexible tube about the thickness of a pen, fitted with a light source and camera at its end.
The fiber optic camera takes pictures of the inside of your rectum and large intestine while the doctor gently advances the tube. Since the tube is flexible, the doctor is able to move it around the bends and curves of the large intestine.
A colonoscope can be used to examine anywhere from your rectum through the whole of your large intestine to your cecum, under direct vision. Although it is an invasive procedure, it remains the best way to diagnose colon cancer, polyps, and inflammatory bowel diseases.
There are two forms of colonoscopies - traditional direct vision colonoscopy and virtual colonoscopy. We would discuss traditional colonoscopy here.
A colonoscopy can screen for colorectal cancer, which includes both colon and rectal cancers.
In the United Kingdom, in 2010, 40,695 people were diagnosed with colon cancer and there were 15,659 deaths from this cancer in 2011.
According to the American Cancer Society, colorectal cancer is the third leading cause of cancer-related deaths in the United States.
The American Cancer Society estimates that there were 50,830 deaths due to colon cancer in 2013. Early diagnosis and treatment is the key to survival.
Colonoscopy save lives.
There are several reasons why your doctor may order a colonoscopy. They include:
The single most important thing you can do to help ensure that you have a successful colonoscopy is to prepare for the test.
You may have heard a lot of people say that colonoscopy is a terrible experience. They often say the worse part of it is not the procedure itself, but the fact that you have to take a laxative to clean your bowls.
Yes. Before you have a colonoscopy, you will be given a "colon prep" to clean out the colon.
Colon prep is done by using a form of laxative called PEG-based laxative. You would be instructed to buy one yourself from your local pharmacy or online. They come in different brand names, and these names may be different depending on where you live. Popular preparations include Peglyte, Colyte and Golytely.
There are universally accepted colonoscopy preparation kits that you can get online containing Miralax and Dulcolax. This kit is usually acceptable for most colonoscopies - be sure to clarify with your endoscopist if they are happy with you using this kit. You can also get the Miralax and Dulcolax Colonoscopy Prep Kit for diabetes if you suffer from diabetes.
The liquid or laxative you drink for the colon prep will cause loose stools or diarrhea, so your doctor can clearly see the walls and the interior, or lumen, of your intestine. You will also be on a liquid diet for about a day before your colonoscopy.
You may be asked to give yourself an enema as well, to clean things from below. An unclean colon can lead to a longer exam, and carries an increased risk of missing important abnormalities. You should be sure to follow the doctor's instructions closely.
Certain conditions may affect colonoscopy. Prior to colonoscopy, let the doctor know about the following details:
Depending on your age and your risk factors, you may have screening colonoscopies recommended every five to ten years. Your doctor will follow guidelines based on evidence that regular colonoscopy prevents death and disease from colon cancer and related conditions.
The following is a step by step guide on when and what to do to properly prepare for your colonoscopy:
At about a week to 5 days before your colonoscopy, you should make sure you are very familiar with what this test is about, have all your questions answered and start changing your diet to make sure you can have an effective colon cleanse.
You will need to start a "low residue diet".
A low residue diet is a diet low in fiber. This includes food like:
You will want to avoid the following foods before your colonoscopy:
The day before your colonoscopy, you should:
As mentioned above, it is the bowel prep that many find more troubling during colonoscopy preparation than the colonoscopy itself. To help minimize the effect of your colon prep on you, the following are practical advice you might find useful:
The day has finally arrived for your colonoscopy. You should continue to drink clear fluid until 2 hours before your procedure.
We cannot stress enough the importance of drinking enough amount of clear fluids.
Poor preparation of your bowel and not having enough fluids can cause poor results and need to repeat your colonoscopy again. Dehydration due to inadequate fluid intake can also cause you to become weak and even faint or collapse.
Here are what to expect during your colonoscopy appointment:
While performing your colonoscopy, your doctor will be able to take tissue samples, or biopsies, which will be examined under a microscope by a pathologist for signs of abnormal tissues or cells.
When you have your colonoscopy, you will be sedated and will not have any discomfort. You will not remember the colonoscopy after the test. However, your doctor will come in to inform you of the results of the test, and will probably show you some pictures that were taken during the test. If biopsy samples are taken, your doctor will follow up with you and let you know the results within a few days.
Colonoscopy is a very safe procedure.
Although the risk is small, the colonoscope or one of the instruments your doctor may pass through the tube, such as the forceps used to collect biopsy samples may tear the lining of the large intestine, and may cause bleeding or a perforation. If this should happen, you will require surgery.
After the colonoscopy, call the doctor if you have:
Most times, a colonoscopy result would come back as normal. This means that the lining of the wall of the colon is smooth and pink, with no obvious bumps or projections or indeed thickening or ulceration or pouching.
Some other times, the result could suggest the presence of:
Whatever the result, your doctor would explain this to you as well as help you plan what next, by way of treatment.
How often should colonoscopy be repeated? Well, it depends on your particular risk factors as well as what was found during your colonoscopy.
The following is a guide. Your doctor would advise you on exactly what applied to you.
If you have no additional risk factors for colon cancer like:
Then you should have repeat colonoscopy every 10 days.
In the time interval, your doctor may still decide to have you do an annual FIT test.
If your FIT test becomes positive anytime, then you would require urgent colonoscopy.
If you were found to have:
You are most likely going to need to have repeat colonoscopy every 5 years, with FIT tests done annually, to offer another layer of surveillance.
You are likely to be asked to have repeated colonoscopy every 3 years if:
There are lots of stories of patients who develop colon cancer after a normal colonoscopy. This is sadly true.
This is because colonoscopy is known to have a miss rate of 6 to 27%. This means that in 6 to 27 patients out of a 100, colon cancer could be missed during a colonoscopy and this may thereafter progress and become apparent later.
While it is still the best method known to detect colon cancer, it is not a foolproof method. It is notwithstanding, worth having colonoscopy.
This miss rate of 6% or more could be for any of the following reasons:
You can develop colon cancer 1, 2, 3, or 5 years after a normal colonoscopy. This raises the question - how long does it take for colon cancer to develop?
All polyps eventually become cancer if they have enough time to develop and have the environment (lifestyle, diet and genetics) to support such growth. It is known that polyps take 5 to 10 years to become cancerous.
So for this reason, it is always advised that even after having a colonoscopy, you should have a regular check with your doctor and have a FIT test if possible as advised by your doctor.
Are you about to have a colonoscopy? Or have you had one? Do you have a great story or question about this? Share it!