Human: My doctor says that I need to get a colonoscopy. What does that mean and how often do I need to do it? Assistant: 
A colonoscopy is a procedure in which a doctor uses a long, flexible tube called an endoscope to examine the inside of your colon. It is usually done in a medical office or hospital setting. The doctor will insert the endoscope into your rectum and slowly move it through your colon, taking pictures as he goes. The entire procedure takes about 30 minutes to complete. Afterward, you may have some cramping or discomfort for a few days. You should not drive yourself home after the test, but can arrange for a friend or family member to pick you up.