This is a video of a colonoscopy with a very bad colon preparation. This patient did not follow the prep directions, ate before the procedure, and did not drink the bowel prep as prescribed. As a result, the visualization of the colon was very poor, obstructed by semi-solid fecal material. Since we are screening for colon cancer, it is virtually impossible to see all polyps or tumors. As a result of the poor preparation, he had to come back for another procedure. The lesson of this video is to follow the bowel preparation exactly as they are given, and to encourage patients to ask questions regarding the prep prior to starting if they have any concerns.