Colonoscopy means the examination of the large intestine with an endoscope. Endoscopy is performed with a small, long and flexible tube. Inside the tube there is a light source and a camera through which the image of the examined section of the intestine can be projected and followed on screen.
The examination usually takes 30 minutes. However, sigmoidoscopy (examination of the last part of the colon) usually takes less than 15 minutes.
The endoscope enters the bowels through the rectum which might cause the patient to experience pressure or spasms in the abdomen.
The endoscopic examinations mentioned above might be used for detecting inflammations of the large intestine, removing polyps or taking tissue samples. They can reveal the source and cause of intestinal bleeding or pain and can also help diagnosing colon and rectal tumors.