A very important aspect in the patient's evaluation is the analysis
of the extracted or fragmented stone. Within 2 days of patients
having symptoms related to stones, approximately 70-80% of stones
will pass spontaneously in the urine. On the other hand, if patients
underwent a procedure for stone treatment, their maybe stone fragments
that broken up but not yet removed. Therefore, it is very important
to collect any stone fragments that may pass in the urine. Patients
are asked to urinate into a strainer, a cup with a mesh in the bottom,
to retrieve the stone fragments. All stones fragments, no matter
how large or small, should be collected and sent for stone analysis.
This evaluation is essential and will shed light onto the etiology
and pathogeneses of the renal stone so that therapy can be optimized.
Four to six weeks after a patient has passed his or her stone, or
after it has been removed or disintegrated a 24-hour urine specimen
will be obtained. It is important that the patient remain on his
or her regular diet and life style during this period of urine collection.
Urine is collected over a 24-hour period beginning with the second
urine on the first day and ending with the first urine on the second
day. This urine collection will be studied for chemicals in the
urine that promote and inhibit stone formation. The specimen is
analyzed for total urine volume, calcium, phosphorous, uric acid,
creatinine, oxalate, magnesium, sodium and citrate.
Patients who had a history of kidney stones are prone to developing
stones in the future. In fact, patients who develop stones, have
a 50% risk of developing another stone within 5-10 years, and about
80% chance sometime in their life. To reduce a patient's risk of
developing another stone, there are proactive measures that you
and your urologist can take. Based on the stone analysis and the
24-hour urine collection, we can determine the type of stone and
stone forming substances that may increase your risk for future
stone formation. Therefore, we can determine if certain dietary
changes and/or medications may reduce your risk for future stone
formation. In addition, one of the most important factors for reducing
all types of stones is by drinking large amounts of fluids. Patients
who make kidney stones should drink of fluids to make 2 liters of
urine or about ½ gallon of urine daily. Since the goal is to produce
2 liters of urine daily, you may find it necessary to drink more
fluid in hot weather or if you perspire from athletic activity,
etc. to replace the fluid lost by sweating.