Crohn's and Kidney Stones: What's the Connection?

Among many other symptoms, Crohn’s disease may lead to the formation of kidney stones, known scientifically as urolithiasis. One of the most common complications of IBD, kidney stones are fortunately one of the less serious symptoms, although they can be quite painful.

People with Crohn’s disease in the small intestine are more at risk for urolithiasis due to the body’s failure to absorb fat. When fat deposits and calcium are near each other, the fat binds to calcium due to a chemical affinity to calcium. After the fat and calcium bind together, the fat leaves behind a salt crystal known as oxalate, which adhere and cluster together to form stones.

People who have had multiple small bowel resection, or small intestine surgery, are more prone to develop kidney stones because their urine is more concentrated and are more likely to become dehydrated. Luckily, the prognosis is good for those with this type of stone. Implementing a vegetable and juice diet, which is low in oxalate, and drinking more fluids generally solves the problem.

Uric acid stones can also occur

Crohn’s disease can also lead to uric acid stones. Can you guess what uric acid stones are composed of? You got it! Uric acid crystals. According to Dr. Ferrari, who has extensively studied kidney stones in those with CD, when urine drops in pH level and becomes too acidic, lower than 5.5, uric acid crystals form. Alternatively, if there is too much uric acid in urine, the crystals are more likely to solidify.

There are 5 significant factors that make one prone to kidney and uric acid stones:

• Metabolic Abnormalities
• Diet
• Antibiotics
• Altered Intestinal Permeability
• Obesity Treatments

Metabolic abnormalities

Typically indicating the first signs of Crohn’s disease, metabolic anomalies refer to biological quantities that are considered abnormal. For example, low concentrations of citrate (known as hypocitraturia) and low concentrations of magnesium in urine (hypomagnesemia) often contribute to kidney stones. Naturally produced by the human body, citrate works by directly inhibiting calcium oxalate crystallization and also by forming calcium soluble compounds that can be excreted by the body. Therefore, low concentrations of citrate result in high concentrations of calcium oxalate.

Additionally, low urine pH levels, abnormally high levels of oxalate, and urinary volume all play a role in the formation of kidney stones. Dehydration is one of the most common reasons for kidney stones and is the easiest to fix. High concentrations of oxalate in urine (called hyperoxaluria) can occur for a number of reasons, such as overproduction due to metabolism imbalance, eating foods containing lots of oxalate, and high intestinal absorption of oxalate.

Read on to learn more about the occurrence of kidney stones in Crohn's disease.