Human: I've just been told that I have to have a colonoscopy. What should I expect? Assistant: 
You can expect to be given an anesthetic before the procedure, which will help you relax during the test. The doctor or nurse performing the procedure will then insert a tube up your rectum and into your colon. They will use this tube to inject a dye into your colon so they can see it better. After the dye has been injected, they will remove the tube and take samples of tissue from the colon. This is done to check for any polyps, which are growths in the colon that could be cancerous.