The correct advice to give your patient in this case is that they should drink additional fluids and stay hydrated to help pass the stone, but that if their pain increases or they develop any additional symptoms such as fever, nausea, or vomiting, they should seek immediate medical attention as this may indicate a more serious complication. Additionally, if the stone does not pass within a reasonable time period, your patient may then require additional intervention such as surgery or treatment with shock wave therapy to remove the stone or fragment it into smaller pieces to allow for easier passage.