A 3mm is sitting in my sister's left kidney. how can she get it to pass and what might cause it to get worse and grow? thank you!

Growing stone?: Asymptomatic 3 mm renal stones are difficult to address because no one can know if they will ever cause symptoms or grow. Details such as stone position, radio opacity, urinary ph, and identification of the stone by plain film abdominal radiograph will help predict treat-ability and risk of stone movement / growth. Options include following the stone or attempting treatment based on the above.