Besides colonoscopy, bowel cancer can also be ruled out through tumor markers, fecal occult blood test and imaging examination, etc. The details are analyzed as follows: 1. Tumor markers: Carcinoembryonic antigen and CA199 are tumor markers that need to be tested for patients with suspected bowel cancer, which can help to assist in diagnosing the condition. 2. Fecal occult blood test: it is one of the main screening methods for bowel cancer, mainly used for checking small amount of bleeding that is not visible to the naked eye. It is fast, simple and painless. 3. Imaging examination: such as gas-barium double-contrast imaging is one of the more commonly used and economical means to diagnose bowel cancer. In addition, CT and MRI (Magnetic Resonance Imaging) examination are more frequently utilized nowadays.