Hello there....... Most stones that cause renal colic are small and pass out with the urine in a day or so. You should drink plenty of fluids to encourage a good flow of urine. Strong painkillers are often needed to ease the painuntil you pass the stone. No other treatment is usually needed. Some stones that form and stick in the kidney do not cause symptoms or any harm. They can just be left if they are small. ...,,... Consult your urologist for further advice.....