The clinical manifestations of colitis and colon cancer are as follows. Inflammatory colon disease can often present with symptoms such as fever, abdominal pain and diarrhea. Colon cancer usually has no clinical manifestations in the early stage, but in the progressive stage, the common manifestation is the change of stool characteristics and habits. The change of stool characteristics is unformed stool or color change from yellow to black or red, and the change of stool habit is 2-3 times a day, or only once every 2-3 days, and the gap of formed stool. Because of the tumor, the deformed stool will appear. In advanced stage, tumor mass, intestinal obstruction, abdominal pain, blood in stool, etc. will appear.