It is theoretically possible to detect suspected bowel cancer without colonoscopy, but clinically the final diagnostic criterion is still the pathological tissue removal test under colonoscopy, so it is unlikely to confirm the diagnosis of bowel cancer without colonoscopy. Bowel cancer refers to tumors whose primary site is in the intestinal tract, colonoscopy can directly enter the intestinal tract and accurately find out the location of tumor onset with the help of camera, and it can also help to take out the pathological tissues from the tumor site through colonoscopy for testing in order to diagnose the nature of the tumor, so at the current level of medical science, it is very difficult to confirm the diagnosis of bowel cancer without doing colonoscopy. In addition to colonoscopy, there are also new bowel or cancer detection technologies in application, such as intestinal CT, genetic testing, etc. These methods are less painful to patients compared to colonoscopy, and the examination process is also more convenient, but these methods can only be used for cancer screening, patients with suspected cancer still need to go through the colonoscopy to take out the pathological tissues to confirm the diagnosis.