Kidney stones are accumulations of crystal materials that have separated from your urine in the urinary tract and have clumped together. Many times kidney stones pass through the urinary tract without any problem. However, sometimes they get stuck and require various treatments to break up the mass and help pass the kidney stone. These stones can be very painful to deal with but you can eat certain food to help pass kidney stones.
High-Calcium Foods
Doctors used to believe that individuals trying to pass calcium kidney stones---or those with a tendency to develop calcium kidney stones---should avoid calcium. However, at least two scientific studies referenced by the Cleveland Clinic report that a minimum of two servings of high-calcium foods each day can help reduce the rate of development of calcium-containing kidney stones. Foods high in calcium include milk, cheese, yogurt, leafy green vegetables and oranges.
Water
Water may seem obvious, but it's extremely important to both passing and preventing kidney stones. According to the Cleveland Clinic, you should drink enough water to produce 2 qt. of urine in every 24-hour period. This can mean consuming a gallon of water a day and sometimes more, and some of this water consumption should occur at night. Flushing your body will also help flush your urinary tract, making it easier to pass kidney stones.
Low-Sodium Foods
An important task in passing kidney stones is to reduce the presence of sodium in your diet. According to GICare.com, sodium can cause an increase of calcium present in the urine, which can result in a greater tendency to develop calcium stone formation. While you shouldn't add salt to foods you consume, you should also stick to fresh fruits and vegetables and use natural meats instead of processed meat. Avoid canned soups and make your own, and purchase low-sodium options whenever possible.
Whole Grains
Whole grains are high in insoluble fiber. The Cleveland Clinic reports that this type of fiber attaches itself to calcium and helps pass the calcium through your stool instead of the kidneys, reducing your risk of kidney stones containing calcium. Try to eat whole wheat, rye, barley and/or rice to keep your urine clear of threatening minerals.


