How a colonoscopy is performed
Article
|Last update
If blood is detected in your stool sample, you will be referred to a colonoscopy at the hospital. During the procedure, the inside of your bowel will be examined.
How a colonoscopy is performed
During a colonoscopy, a soft, flexible tube is inserted into the colon through the anus. Through the colonoscope, tissue samples can be taken and treatments can be performed, such as removing polyps.
To clearly see the lining of the bowel, the entire colon must be cleaned beforehand. There are several different methods and preparations for bowel cleansing. Often, a laxative powder is mixed with water and taken in two doses: half in the afternoon the day before, and the other half in the morning on the day of the examination.
The procedure takes about 30 to 40 minutes but can sometimes take longer. One in four people experience discomfort or pain. If needed, you can be given a sedative or pain relief medication. In that case, you must not drive until the next day.
This video shows how a colonoscopy is carried out (in Norwegian):
Polyps
Polyps are wart-like growths inside the colon that can be removed during a colonoscopy. This is done by placing a metal loop around the polyp and cutting or burning it off. This does not hurt because there are no pain-sensing nerve endings inside the bowel.
Polyps are common and usually cause no symptoms. At least 9 out of 10 polyps will never develop into cancer. The few that do may take 10 to 15 years to become cancerous. The size and appearance of a polyp can give an indication of the cancer risk, but it is also important to examine them under a microscope. That’s why all polyps are removed and sent to analysis.
Complications during a colonoscopy
Complications such as bleeding or a tear in the bowel occur in about 1 to 7 out of 1,000 colonoscopies.
These are usually treated immediately during the procedure, but some people may need to be admitted to the hospital.
Some complications may occur several days after the examination. If you experience severe abdominal pain, fever, or blood in your stool, it is important that you contact the hospital.
Contact the screening centre if you have special health considerations
The screening programme does not have access to information about your medical condition.
If you have been scheduled for a colonoscopy, you must contact the screening centre well in advance if you:
- are taking blood-thinning medication
(for example, Marevan, Eliquis, Pradaxa, Xarelto, Plavix, Effient, or Lixiana). You may continue using Albyl-E or other acetylsalicylic acid as usual. - have a pacemaker or defibrillator
- have chronic heart, lung, or kidney disease
- are currently undergoing, or have recently undergone, treatment for a serious illness
- are in poor general health or in need of care
- are taking medication for diabetes
- have been diagnosed with an infectious disease or have been admitted to a healthcare facility outside the Nordic countries within the past 12 months