There are a variety of organs to the left of the navel, in order from the outside to the inside: first point, the wall muscles are mostly the rectus abdominis, external oblique abdominis, internal oblique abdominis and transverse abdominis. The second point, the wall layer peritoneum is the deep part of the muscle, which mostly shows limited peritonitis with pressure pain and rebound pain when local infection occurs. The third point, jejunum is the proximal small intestine, mostly combined with intestinal obstruction, gastrointestinal mesenchymal tumor, and fecal stone impaction. The fourth point, descending colon and sigmoid colon, when tumors appear, they mostly manifest as stool color, change in nature, and also have pressure pain on the left side of the navel. The fifth point, the left kidney and left ureter, if combined with tumor or stone infection, in addition to pressure pain on the left side, there is often percussion pain on the left side of the back, along with frequent, urgent and painful urination.