The left lumbar region is mainly the descending colon, jejunum, ileum, and left kidney, and the left lumbar region is also called the left abdomen. There are two methods commonly used for the zoning of the abdomen: one is the four-district method, and the other is the nine-district method. The left left lumbar region is obtained according to the nine-distinction method, and there are two horizontal horizontal lines and two longitudinal lines in the partitioning, from the line connecting the lower edge of the rib arch on both sides, and the line connecting the anterior superior iliac spine on both sides, two are horizontal lines, and the midpoint of the line connecting the anterior superior iliac spine from the left and right to the abdominal midline as two vertical lines, and the four lines divide the abdomen into nine areas in the shape of a well, which are called the left and right upper abdomen, also known as the quarter ward, the left and right lateral abdomen also known as the lumbar region, and the left and right lower abdomen, also known as the iliac region, which also divides the abdomen into the upper, middle and lower abdomen, so the left abdomen is also known as the left lumbar region. The left lumbar involves mainly organs of the digestive system, such as the alimentary canal, and also the kidneys of the urinary system, which are mainly located outside the peritoneum and not inside the abdominal cavity, while the digestive canal is mainly there is mainly inside the abdominal cavity.