Colonoscopy

What is the purpose of this test?

A colonoscopy allows to look inside the large intestine and can be recommended for a variety of reasons:

• Diagnosis and follow-up of inflammatory bowel diseases (e.g., Crohn's disease and ulcerative colitis).
• Identifying the cause of persistent bleeding or a change in stool.
• Follow-up of abnormal results from other tests, such as a fecal occult blood tests.
• Detection and possible removal of polyps (small masses that have developed in the intestine).
• Detection of suspicious growths or colorectal cancer.

Preparation

The colon generally holds feces. To get a clear view of the colon, it is crucial that it be emptied and cleansed. Various laxative preparations are commonly used to that end. Each health care facility has its own protocol. Before going for a colonoscopy, make sure that you have read all the instructions that were given to you on how to prepare and make sure that you have all the medication needed to prepare for the procedure.

The protocol usually includes:

• A special diet in the days before the exam.
• One or more laxatives to be taken the day before and the day of the exam.
• Certain medications to be suspended in the days preceding the exam.

The following table contains a list of products that may be included in your colonoscopy preparation.

Many patients have difficulty tolerating certain formulas. This can lead to inadequate preparation and an incomplete colonoscopy. However, certain measures can improve tolerability:

• Chilling the solution.
• Using a straw to drink the solution.
• Using low-volume formulas.
• Using split-dose preparation (e.g., taking one dose the day before and one dose the day of the procedure).

Nausea, vomiting, and abdominal pain may occur. If these symptoms persist or worsen, the procedure should be discontinued. The same applies if there is any sign of dehydration (e.g. thirst, dizziness, decreased urination) or the onset of a fever.

Procedure

Colonoscopies are performed at a hospital or specialized clinic. The exam usually takes place as follows:

• You'll first be asked to change into a hospital gown.
• You'll be given a sedative to help you relax, but you'll remain conscious during the procedure.
  • You may not remember what happened during the exam.
  • It may take time for the sedative to wear off after the procedure, so you won't be able to drive. Be sure to arrange for someone to help you get home.
• You'll be asked to lie on your left side with your knees drawn toward your chest.
• The colonoscope will then be inserted through the rectum to examine the inside of your colon.
  • Air is sometimes introduced into the colon to get a better view of the lining.
  • Certain procedures may be performed during the colonoscopy, such as polyp removal or biopsies (removal of small tissue samples).
• A colonoscopy generally takes 30 to 45 minutes to complete.

What to look out for after the examination

Although very rare, complications can occur. If you experience persistent bleeding, significant pain, fever, nausea or vomiting after the procedure, immediately contact the centre where you had your colonoscopy.

Meaning of test results

You will be informed of the results during or after the exam. However, if tissue samples were taken, it may take a few days for them to be analyzed. Colonoscopies are used to diagnose various intestinal problems, including inflammation, infection, hemorrhoids, ulcers, polyps, diverticula, and cancerous lesions.

A colonoscopy can also confirm that everything appears normal.

What you should know before going for this test

When you go in for a blood test or any other medical exam, it's always a good idea to bring a complete list of any prescriptions, over-the-counter medications, or natural health products you're taking. Unless otherwise advised, it's best to take your medications as usual on blood test days. If in doubt, don't hesitate to talk to your healthcare professional.