Physicians have not successfully predicted which individuals will resist health care measures, such as cancer screening. Many people who agree to have screening for colorectal cancer do not keep the appointment. In colon cancer screening, known as endoscopy, a flexible tube is inserted to directly inspect the inner lining of the bowel wall. Reasons that some people decide not to have screening range from the need to prepare the bowel to concern that the procedure will be painful. Some people may not realize that early cancer detection results in better outcomes. Those who decide not to keep their cancer screening appointment may also miss more scheduled physician appointments. These patients could be targeted for special measures so that they are more likely to attend screening.