Colonoscopy is an internal exploratory examination of the large intestine. With an endoscope, the doctor looks at the mucosa at the inside of the large intestine and optionally the last part of the small intestine. This examination is carried out in order to detect or exclude any defects. Colonoscopy is a type of endoscopy.


With a colonoscopy, almost all defects of the colon can be detected. A colonoscopy is performed in patients with hereditary predisposition to colon cancer, in people with a lot of polyps in the colon and when a bowel disease or bowel defect is suspected.


The endoscope is a flexible tube of about one centimeter in diameter. At the end of the tube, there is a small light and a camera. The light ensures that the doctor has good vision. The camera is connected to a monitor, on which the doctor can follow the examination.


For this examination, it’s important that the colon is clean and empty. Therefore, prior to the examination the patient needs to purge at home. During a colonoscopy, the patient is lying on his left side on the examination table. Through the anus, the doctor inserts the endoscope into the rectum. From here, the doctor moves the endoscope still further into the intestine. During the examination, small pieces (biopsies) can be taken from the lining, for further investigation into any mucosal defects. Also polyps (benign tumors) can often immediately be removed.
Insertion through the anus and the shifting of the endoscope through the intestines are usually unpleasant for people. If a person has received sedation, he or she notices almost nothing. The examination takes approximately 30 minutes.