A colonoscopy is a test a doctor administers to check for a variety of possible issues concerning the body's health. For example, a colonoscopy could be used to check for colon cancer, checking for the cause of rectal bleeding or chronic diarrhea, to monitor irritable bowl disease or to check for the cause of sudden abnormal weight loss. Before the test the doctor will have the patient do a colon cleanse in order for the colon to be completely clear before the colonoscopy. These cleanses can differ but mainly require patients to stay at home, drink a special fluid and refrain from eating solid food. During the colonoscopy the doctor will insert a thin tube called a colonoscope to view the large intestine and take pictures to determine the health of the colon and large intestine.