If you suffer from kidney stones, you might want to listen to these new guidelines from the American College of Physicians. People should strive to drink excessive amounts, enough that they have two liters of urine a day. If drinking liquid is not enough to produce that much urine, the doctors recommend that you take thizazide diuretic or allopurinol.

These guidelines were published in the Annals of Internal Medicine.

Dr. David Fleming, the President of the American College of Physicians, said that increasing the amount of fluids you drink to much higher amounts can cut kidney stone risk by as much as 50 percent. Drinking more water has no side effects, and is completely safe. However, Fleming said that if you are already drinking excessive amounts of liquid you should not further increase that amount.

Men are at a higher risk for kidney stones than women. In the United States, about 13 percent of men will develop a kidney stone at some point in their lives; 7 percent of women will develop a kidney stone. Kidney stones are more likely to recur in people who have already had one kidney stone.

Kidney stones form when small crystals stick together in urine. The symptoms of kidney stones include pain during urination, which can sometimes be very intense, and blood in urine.

The research study took groups of people who previously had kidney stones, and measured their urinary output. They found that patients who drank enough to have a urinary output of 2 liters a day only had a 12.1 percent rate of recurring kidney stones compared to 27 percent of the control group.

Reducing the amount of dietary animal protein you eat can further lower your risk for kidney stones. So can drinking less soda, according to the researchers.

Current ACP guidelines tell patients with a history of kidney stones to reduce intake of foods high in oxalate, such as beets, rhubarb, spinach, strawberries, nuts, chocolate, tea and wheat bran.

"Efforts to prevent the recurrence of nephrolithiasis target decreasing concentrations of the lithogenic factors (for example, calcium and oxalate) and increasing the concentrations of inhibitors of stone formation (for example, citrate)," the ACP wrote in the research paper. The paper's lead author was Dr. Amir Qaseem.