The time when stones smaller than 1cm can be expelled from the body depends on the size and location of the stones and the measures taken for stone removal, which requires comprehensive analysis and cannot be generalized. If the stone is smaller than 0.6cm, usually the stone can be discharged smoothly in about 2-48 hours through medication, such as oral lithotripsy granules, together with drinking more water and exercising. If the stone is relatively large, between 0.6cm and 1cm, it is less likely to be discharged by conservative treatment and extracorporeal shock wave lithotripsy should be considered. In addition, patients should also be aware that if the stones are embedded for a longer period of time, they may not necessarily be expelled by extracorporeal shock wave lithotripsy and may need to be considered for surgical treatment.