First of all, you should have enough time for indwelling D-J tube in ureter (usually 2 to 3 months), drink plenty of water at ordinary times, and don't hold your urine. Because the catheter is a foreign body, stones often form along the wall of the catheter. The success rate of this operation is not 100%. After extubation, there is likely to be water accumulation, which requires re-intubation.