Abdominal ultrasound can detect middle and late stage intestinal cancer. Abdominal ultrasound is mainly good at observation of substantial organs, such as liver, kidney, uterus and so on. For cavity organs such as stomach and intestinal canal, the examination is not sensitive, because gas often exists in cavity organs, and ultrasound will be attenuated when encountering gas, and the display will not be clear, so ultrasound is not very sensitive for intestinal canal examination. Because the lesion of early stage intestinal cancer is relatively small in scope and the degree of infiltration to the wall of intestinal canal is very light, there is no special sign on the ultrasound, so the ultrasound display is not clear. However, in the middle and late stage of intestinal cancer, as the disease develops, the cancer foci destroy the intestinal wall more and more, the structure of intestinal wall is disordered, uneven thickening, echogenic disorder, pseudo-kidney sign, peristalsis is not obvious, so the ultrasound can show more clearly at this time, especially in the late stage, it can be accompanied by enlarged abdominal lymph nodes and ascites, so the ultrasound can basically confirm the diagnosis at this time.