COLONOSCOPY is the use of a flexible, high definition camera to examine the large intestine, also called the colon. Colonoscopy also allows your doctor to biopsy, treat, or remove growths that can occur in the colon such as polyps, thereby helping to prevent colon cancer from developing.

Colonoscopy is typically performed at a hospital here in Calgary, or at a specialized clinic such as the Colon Cancer Screening Centre (https://www.albertahealthservices.ca/info/ccsc.aspx).

Colonoscopy is used to investigate gastrointestinal symptoms of concern such as bleeding from the rectum or anus, abdominal pain, constipation, a concerning change in bowel pattern, weight loss, or abnormal findings on an imaging or screening test such as a CT scan or a stool test.

Colonoscopy can be used to detect pre-cancerous polyps which have the potential to grow and progress to cancer over time, tumors or other growths that can be benign or malignant, inflammation of the colon, structural changes such as narrowing or blockage of the colon, or other conditions such as diverticulosis.

High definition flexible colonoscopes have small channels that allow physicians to pass instruments to take biopsies or remove polyps at the time of your procedure. Any tissues or growths removed are collected and sent to the pathology lab for analysis.

PREPARING FOR YOUR COLONOSCOPY

A successful colonoscopy procedure relies on a good preparation. It is critical to clean out stool from the bowel to allow the physician to clearly see the walls of the colon, which will help them to detect any growths or abnormalities. A clean colon can also help shorten the time it takes to complete your procedure. To prepare for a colonoscopy, you need to change your diet in the days leading up to the test, and need to complete a bowel preparation which is a specially formulated drink used to clean out stool from the bowel.

By the end of your bowel preparation, the liquid you are passing into the toilet should be clear or nearly clear with a slight yellow tinge. If you are still passing out solid stool or dark brown liquid that you cannot see through, please alert your nurse or physician as you may require an enema to clear remaining stool from the bowel.

If your bowel is not clean enough your physician may not be able to complete an adequate examination. The doctor may not be able to safely pass the colonoscope all the way to be beginning of the large bowel if they cannot clearly see, or may not be able to properly examine the walls of the bowel to be sure there are no polyps, growths, or other abnormalities. In these instances you may be recommended to repeat the test sooner than you otherwise would if you had a clean bowel. This is why having a good “prep” or bowel cleanse is so important.

THE PROCEDURE

A colonoscopy procedure typically takes anywhere from 15-30 minutes depending on how windy or twisty the bowel is. The physician will pass the colonoscope from the anus to the beginning of the colon, where the small intestine meets the large intestine, and then will slowly withdraw and remove the colonoscope carefully checking the lining of the colon for any growths or other abnormalities. During the procedure the physician may put water or carbon dioxide into the bowel to allow a better examination of the colon wall for any abnormalities.

It is normal to have some discomfort during the colonoscopy, though your doctor will do their best to minimize this. Discomfort during colonoscopy is temporary and occurs when the bowel feels stretch, such as when going around a tight corner, or due to feeling full from the gas that the physician uses to open up the bowel to examine it. While the bowel does not feel the traditional sharp of a pin prick or temperature such as hot or cold, it does have pressure sensors that feel when the bowel is being stretched.

PAIN CONTROL DURING COLONOSCOPY

We use a combination of medications given by intravenous to provide light sedation and pain control for patients having a colonoscopy. The medications we use can often trick someone into forgetting the procedure or thinking that they were asleep, though we are quite careful with the dosing. Our goal is your comfort, rather than trying to make you sleep through or forget the colonoscopy test. Most patients are awake through the procedure.

Many individuals have minimal discomfort during the procedure and watch the test on the video monitor. Some individuals complete their procedure without any sedation which shortens their stay after the procedure and allows them to drive themselves to and from their appointment.

On the other hand, some patients have a long, winding (“twisty or tortuous”) bowel and can find the procedure uncomfortable or even painful. This is a smaller subset of patients. We do our best to adjust the medications that we give to keep you as comfortable as possible through the procedure. Certain conditions such as narrowing of the colon, or diverticulosis (also called diverticular disease) can lead to more discomfort during the colonoscopy test.

RISKS OF COLONOSCOPY

Colonoscopy is a very safe and common procedure, however, like all procedures it does carry some risks. The rate of serious complications from colonoscopy is very low, far less than 1%, but important risks to consider include bad reactions to the preparation (bowel cleanse) including nausea or vomiting, abdominal discomfort, or possibly electrolyte imbalances. If you are on dialysis, please alert your colonoscopy physician and your kidney specialist as the preparation for the colonoscopy may be slightly different. Serious risks that can happen during the procedure include causing a hole or tear in the bowel wall, or serious bleeding, which can occur when taking larger polyps off of the colon wall. This is not common, but if it occurs it can be serious and life threatening and can require emergency surgery to repair. Colonoscopy is a very good test for detecting polyps, but no test is perfect, and it is possible to miss polyps and even cancers with a colonoscopy. The quality of the colonoscopy depends a lot on how clean the colon is, which allows the physician to have a good inspection of the bowel.