In human anatomy, the cauda equina plexus, which runs in the lumbosacral spinal canal, is involved in the innervation of defecation and urination. Why does a severe lumbar slippage cause loss of control of the second stool? When vertebral slippage is serious (lumbar slippage of degree II or above), it is often accompanied by protrusion of the intervertebral discs, resulting in narrowing of the spinal canal space, which is the technical term for spinal stenosis, causing the cauda equina to be squeezed, resulting in the loss of its normal neuromodulatory function and the clinical loss of control of the bowel movement due to its lack of power. The lumbar spinal canal is like a hose, and the cauda equina is like the water that passes through it. When the lumbar spine slips, the vertebrae are displaced, and the spinal canal changes, just like bending a water pipe, the water flow through it is bound to become smaller, and the cauda equina is squeezed, resulting in the loss of control of the second stool. In this case, the narrowed spinal canal space can be improved through surgery, and the compression of the cauda equina nerve can be removed as soon as possible to restore its function, so that the two bowels can be controlled freely.