How long does it take to get rid of fluid caused by stones is mainly related to the size of stones, the severity of fluid and the treatment method, which should be analyzed specifically and cannot be generalized. If a small stone causes hydronephrosis within a short period of time, patients can be treated with oral lithotripsy and antispasmodic drugs, and if necessary, surgical lithotripsy can be performed. After the stone is discharged or eliminated, the symptoms of hydronephrosis can be gradually relieved, and the specific elimination time varies from person to person, generally within a month will recover. If the symptoms of hydronephrosis are not eliminated after the stone is discharged, it is mainly due to a longer period of hydronephrosis, a larger amount of hydronephrosis or a combination of other conditions such as infection, which can persist. If the kidney function is not affected, attention to regular observation is sufficient. During the treatment period, patients should carry out a low-calcium diet and try to eat less animal offal, dairy products, spinach, tofu, chili peppers and other foods.