CT examination can be done for the gastrointestinal tract, and enhanced CT is usually performed. for intestinal tumors, CT can observe the size, location, and general shape of the tumor, as well as the relationship between the tumor and the intestinal wall, and the presence of enlarged lymph nodes outside the intestinal tract, but CT cannot visually observe the degree of damage to the mucosal surface in the gastrointestinal cavity like gastroscopy, as well as pathological biopsy after the occurrence of a tumor. When an occupying lesion is found in the gastrointestinal tract, a combination of the two examinations should be performed to complement each other’s strengths and weaknesses, allowing for a more comprehensive assessment of the condition and a more accurate and optimized plan. In addition to CT and gastroscopy, whole gastrointestinal tract barium angiography can be performed to observe the gastrointestinal motility function. The three can be combined with each other and have their own advantages and disadvantages for different diseases.