Bariatric Surgery and Kidney Stones

Stephen Vijan, MD, Urologist

I was sitting at the nursing station at Riverside Methodist Hospital today after making rounds on my patients and noticed Stephen Vijan, MD, a urologist, sitting next to me writing a progress note on one of his patients who was on the same nursing floor. I told him I had noticed that not infrequently my bariatric surgery patients have kidney stones in the first year after their operation but I rarely heard about kidney stones thereafter. He thought it was probably because of 2 reasons:


1). They may have more difficulty drinking as much as they should for a few weeks or months after a bariatric operation.

2). They are probably breaking down muscle as well as fat as they lose weight rapidly. Breaking down muscle increases the amount of uric acid in there blood steam and in the urine as it is cleared from their system. Increased uric acid in the urine is known to increase both uric acid stones and more importantly it increases the development of calcium oxalate stones which are the more frequent type of kidney stones.

Dr. Vijan went on to give 5 suggestions for my patients to help prevent kidney stones:

1). Drink as much as possible up to 2 to 2.5 liters. (I am fully aware that this is not possible early after bariatric surgery but do your best.)

2). Take the recommended calcium citrate with meals. This way the calcium will bind the oxalate keeping it in the intestine and away from the urine. Also, the citrate in the calcium citrate will be excreted in the urine and will decrease the acid milieu in the urine making it more difficult for kidney stones to form.

3). When possible avoid oxalate rich foods. This includes cranberry juice, nuts, chocolate, and colas.

4). Be careful not to take too many dairy products such as milk and cheese as they can contain too much protein. (Of course we wnat you to take 60 grams of protein a day for women and 75 grams of protein daily for men. Early on this is challenging and your first priority after keeping hydrated.)

5). Finally, taking other citrate products can help. He suggested that Theralith pills. This is medicine you can order over the internet from Therologics.

A water pill like hydrochlorothiazide can help but since it is likely to cause dehydration in our bariatric patients I would not advise this medicine for most patients.

Dr. Vijan agrees that this problem is likely to be temporary and will not continue to be at risk for kidney stones after they are able to drink 2 to 2.5 liters of liquid a day and after they have lost most of their weight.

Many thanks to Dr. Vijan for taking the time to explain this to me. I am sure it will help many bariatric surgery patients from all over the world.