Clinically, if the diameter of the stone is less than 6mm, conservative stone removal treatment can be performed. For stones of 6mm size, the general time for stone removal is about 2-4 weeks, and some are smoother and will be expelled from the body in 7-10 days, but it should be judged according to the specific situation. In some cases, there is a congenital narrowing of the end of the ureter, and conservative treatment is not ideal for stone removal. Other stones may be accompanied by urinary tract infections, and the time for stone removal is uncertain because of the serious adhesion of the stone to the ureteral wall and the possibility of forming encapsulated stones. For simple stones less than 6mm, they will be expelled in about 2 weeks after conservative treatment without other factors.