New guidelines could cut risk of kidney stones

Ken Trammell has been struggling with the pain of kidney stones for nearly 20 years -- including right now.

"It comes and goes this time, usually when I get a stone it's constant but this time it's a comes and goes kind of thing," he told CBS News' Bigad Shaban.

It's estimated 20 percent of Americans will develop a kidney stone at some point during their life. Once you have one, you're much more likely to develop another.

The American College of Physicians has just released a new set of guidelines to help patients who are prone to kidney stones reduce their risk for developing them again in the future. A key piece of advice is to drink at least two liters of water or other fluids a day. Research has found that drinking more fluids could cut the chances of recurrent kidney stones by at least half.

"The reason that water is supposedly helpful is that it's a mechanical flushing process so that stone fragments can pass but also so the urine doesn't sediment in the kidney and collect," Dr. Elizabeth Kavaler, a urologist at Lenox Hill Hospital, told CBS News.

The group also recommends dietary changes such as cutting down on red meat and reducing the amount of foods rich in dietary oxalate, a naturally occurring substance that's commonly found in chocolate, nuts, beets and leafy greens.

Additionally, many experts say cutting down on soft drinks can significantly reduce kidney stone risk.

"Soda have oxalates and phosphoric acid in them which both can be major factors in the formation of kidney stones. In addition, soda can be a diuretic so it dehydrates," said Kavaler.

The American College of Physicians says if these dietary recommendations don't help patients prevent subsequent kidney stones, doctors should consider prescribing drug treatments such as thiazide diuretic, citrate, or allopurinol.

Kidney stones occur when there is an accumulation of solid materials in the kidneys. They typically cause severe pain until they are eventually passed and eliminated through urination. Complications related to stones include damage to kidneys and bleeding. The APC says there is not enough evidence to suggest whether conducting tests to analyze a patient's kidney stone compounds is useful for helping to prevent future episodes.