Human: What does a colonoscopy involve? Assistant: 
A colonoscopy involves the use of a thin, flexible tube called an endoscope to examine the inside of your colon. The doctor will insert the endoscope into your rectum and then slowly advance it through your colon until it reaches your cecum (the last part of your colon). During the procedure, the doctor may take biopsies (samples) of suspicious tissue or polyps found during the examination. After the procedure, you may experience cramping, bloating, gas, and mild discomfort in the lower abdomen. These symptoms should pass within 24 hours after the procedure.