Many patients consider kidney stones as simply a very painful nuisance which has to be tolerated periodically. In fact, kidney stone disease is a complex problem with various types of stones and with many different causes. At Urology Centers of Alabama, we utilize state of the art equipment and techniques to successfully treat stones. However, careful evaluation and management options also allow us to successfully prevent recurrent stone episodes in many patients.
What Symptoms are Caused by Kidney Stones?
Everyone knows about the terrible flank pain associated with kidney stones. Many think that this pain is caused by a scratching of the stone as it passes through the ureter. In fact, most of the pain is caused by obstruction of the ureter, causing a backup of urine into the kidney with resultant stretching and dilation of the tissue.
Nausea and vomiting are often present during acute episodes.
Some patients may have an urgency to urinate or blood in the urine. Some patients may even have no symptoms at all.
Types of Kidney Stones
There are various types of kidney stones. The most common are calcium oxalate stones. However, there are also calcium phosphate and uric acid stones and sometimes a combination of two or all three of these. There are also struvite stones, cystine stones, and triamterene stones and other very rare types.
What Causes Kidney Stones?
Stones may develop because of one or a combination of reasons:
Geography – hot, humid climates, such as in our Southeastern part of the county, may increase the risk of stones in susceptible persons by either excess loss of fluids or inadequate fluid intake.
Genetics – many stone patients have a family history of stones.
Diet – see section below on stone prevention.
Medical problems – hyperparathyroidism, gout, chronic diarrhea and several other inflammatory GI problems including some GI surgeries, and others.
Diagnosing Kidney Stones
We currently use a non-contrast CT scan to diagnose most kidney stones. Plain films (KUB) are often obtained and we occasionally utilize renal ultrasound or IVP (intravenous pyelogram).
Treatment of Kidney Stones
There are various methods and equipment used for treating kidney stones, depending on the situation. These options might include shockwave lithotripsy, ureteroscopy, nephroureteroscopy, laser lithotripsy, ultrasonic lithotripsy, stone basket extraction, percutaneous nephrolithotomy, double J stents, and more.
Kidney Stone Prevention
Even though we have a multitude of treatment options and equipment to successfully treat kidney stones, our goal is to help patients avoid recurrent stones. To achieve this, your Urologist might recommend a change in your diet or a special medication.
Calcium stone formers might be advised to drink more water, avoid salt, decrease oxalate intake and avoid calcium supplements. However, keep in mind that we do not recommend restricting dairy calcium. The dairy calcium has the ability to combine with oxalate in the gut and pass out in the feces. If dairy calcium is not available, the oxalate in the gut will be absorbed and sent to the kidneys, where it can combine with calcium in the urine to form stones. If calcium supplements are necessary for osteoporosis, or other reasons, we recommend calcium citrate instead of calcium carbonate in stone formers.
As mentioned above, we might also recommend decreasing intake of oxalate. This is found mainly in tea, strawberries, spinach, and rhubarb, chocolate/cocoa, wheat bran, nuts, and beets. There are many other foods which contain oxalate in lower amounts and we can provide that list if needed. Patients who have uric acid stones will be advised to drink adequate fluids, but also may be advised to cut back on protein in their diet and may be placed on a medication to help alkalinize their urine, or to prevent the formation of uric acid. For recurrent stone formers, who have failed dietary measures, we have developed a kidney stone prevention clinic. This allows us to more aggressively evaluate the patients with various blood levels of calcium, potassium, uric acid, and others, depending on the situation. We evaluate a detailed medical and dietary history. We may also obtain 24-hour urine collections for metabolic evaluation. Medications, such as potassium citrate, may be utilized, as well as others.
Low Oxalate Diet
The following foods and drinks should be avoided when trying to maintain a low oxalate diet:
- Spinach and rhubarb
- Wheat bran
The following foods contain oxalate, but not as much as the above products:
- Dark leafy greens
- Swiss chard
- Draft beer
- Sweet potatoes
- White corn grits
- Instant coffee
- Soy tofu