Constipation refers to decreased frequency of bowel movements, dry and hard feces and difficulty in defecation. Bowel cancer is characterized by abdominal pain, alternating constipation and diarrhea, anemia, fever, etc. Colonoscopy is needed to confirm the diagnosis. Constipation is defined as decreased frequency of bowel movements, <3 times per week, dry and hard feces and difficulty in defecation, which may be accompanied by loss of appetite, lower abdominal distension and pain. It may be caused by organic and functional causes. Organic causes include inflammatory bowel disease, colon cancer and other colorectal and anal diseases, as well as other disease factors such as hypothyroidism and cerebral infarction. Functional constipation needs to go to the hospital for examination to exclude organic factors before diagnosis. And the clinical manifestations of intestinal cancer are mainly changes in bowel habits and the nature of stools, which include constipation, but also diarrhea or alternating between diarrhea and constipation, and the stools may become thinner, and may carry blood or mucus. In addition, there may be systemic manifestations such as anemia and low-grade fever. The final diagnosis is to carry out colonoscopy, if there is a mass to take a biopsy for pathologic examination. In summary, constipation and colon cancer are intertwined. If you have long-term constipation, you should go to gastroenterology department for colonoscopy and other related examinations to check whether there are organic lesions causing constipation, so as to make a clear diagnosis and treat the cause of constipation, so as to avoid delaying the condition.