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Urology/Kidney Stones


Dr. Leslie,

I've had ulcerative colitis for 13 years.  I take prednisone for two to three months at a time to recover from flare-ups.  I'm at about two per year now.  Anyway, I've noticed over the years that I get kidney stones every time I start prednisone.  Especially as I go into higher doses (> 20 mg per day).  I'll start out with cloudy urine, and typically within a few weeks start passing 1 mm or less sized stones (5 to 10 per week and usually most will pass in one or two trips to the bathroom).  They are usually just formed enough to hold together and easily break apart to the touch.

In my most recent round, I passed some 2 to 3 mm in size stones. Probably about 10 of them.  It's bad enough to have sever pain from my ulcerative colitis, but throwing in passing kidney stones at the same time is killer.  I've dealt with them so much that I've realized the pain goes away in about 30 minutes and a little faster if I can muster the courage to walk around and be active afterwards.

I'm curious if the stone material already exists in my kidneys before I start taking the prednisone, and if the prednisone just lowers inflammation in the kidneys and releases the stone material, or if the prednisone is actually leaching the calcium from my system at that quick of a rate.

I'm looking for advice on what to do.  I try to get about 100 oz of water per day (I weigh 145 lb). I'm currently taking calcium 250 mg twice a day and vitamin C 500 mg 2x per day.  I know it impacts the size and frequency of the stones.  I'm not quite sure if it is for the better or not.  I've been diagnosed with osteopenia from the long term prednisone use so I'm looking for how to get my body to keep and properly use that calcium better.  

Can you help me out with understanding why my body is producing so many kidney stones and how to prevent them in the future?  


I also ran across this link:  I'm not sure that it is a very strong correlation based on that.  Unless it means that prednisone used to treat those conditions typically results in increased kidney stones.  Chron's is similar to ulcerative colitis.

Yes, prednisone can increase the risk of stones to some degree, but it's not a major factor.  The mechanism is through increased calcium loss from bone which ends up in the urine as well as fluid retention.  There is also an increased risk of infection so struvite stones as well as calcium stones would be slighly more common.

What you can do to prevent this is to optimize all of the other paramters possible: fluids, salt, citrate, oxalate and uric acid to start with.  A 24 hour urine will determine what chemistries need to be tweaked.  This is not normally done unless the patient already has a history of kidney stones.

For more information on kidney stones and prevention, try to find a copy of "The Kidney Stones Handbook" by G. Savitz and S. Leslie (Yes, that's me!)  You can order a copy from Grant Gibbs, the publisher, at: 530-889-1727 or send an email to  It's a highly recommended, award winning book and the only patient guide for patients written by a urologist and recommended by the NIH.

I am familiar with Crohns and ulcerative colitis.  Both tend to increase kidney stones due to increased transit time, loss of citrate and other factors.

What you need to do is get a 24 hour urine test specfically to look at your urinary chemistry to determine what needs to be addressed and treated to minimize future stone production.


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Stephen W. Leslie, MD


Questions concerning erectile dysfunction, kidney stones and prostate disorders including prostate cancer. I have a special interest in kidney stone disease prevention.


Full time practicing urologist with 30 years experience. Associate Professor of Surgery and Chief of Urology at Creighton University Medical Center. Editor in Chief of eMedicine Urology internet textbook. Author of only NIH approved book written for patients by a urologist on the subject of kidney stones "The Kidney Stones Handbook". Inventor of the "Parachute" and "Escape" kidney stone baskets and the "Calculus" stone prevention analysis computer program.

American Urological Association, Ohio State Medical Association, Sexual Medicine Society

Men's Health, Journal of Urology, Urology, Healthwatch Magazine, Emergency Medicine Monthly, eMedicine, "The Kidney Stones Handbook", and numerous articles in various newspapers. He is also the editor of the Urology Board Review by McGraw-Hill used by urologists to study for their Board Certification Examinations.

Graduate of New York Medical College with residencies completed at Metropolitan Hospital New York, Albany Medical Center and University of Wisconsin-Madison.

Awards and Honors
Thirlby Award of the American Urological Association. Rated as one the country's Best Urologists by the Independent Consumer's Research Institute

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