Although your risk of kidney stones goes up when you have Crohn’s disease, you can take steps to prevent them.
1. Stay Hydrated
When you don’t drink enough fluids throughout the day, your urine can get too concentrated, making it easier for crystals to form.
“Drink plenty of water and electrolyte-containing drinks, especially if you have diarrhea, to reduce stasis [lack of movement] in the kidneys and keep the urinary system moving and well flushed,” says Adrienna Jirik, MD, a gastroenterologist specializing in inflammatory bowel diseases at Cleveland Clinic in Ohio.
You can estimate your hydration levels by looking at your urine, which should appear clear or very pale yellow. The more concentrated it is, the darker it’ll look.
“Never walk past a water fountain,” says Bickston, who heard this adage in medical school and now shares it with his patients. “Stopping to take a few sips — and perhaps top off a water flask — helps avoid dehydration.”
Try to drink up to three liters (about 101 ounces) of fluids per day, and add extra — with electrolytes — when you’re exercising or sweating on a hot day.
2. Eat Less Oxalate
You consume oxalate through several types of foods, which you can limit to avoid kidney stone formation. “Reduce the consumption of high oxalate foods, such as spinach, potatoes, beans, nuts, and chocolate,” says Dr. Jirik.
To lessen oxalate in your system, you can also decrease your intake of animal proteins like meat, poultry, fish, and eggs. These proteins can make your urine more acidic, which increases your risk of forming calcium oxalate kidney stones.
Experts recommend limiting your intake to 6 to 8 ounces (oz) of animal protein per day for the best results.
Although these limitations may protect against kidney stones, you still have to balance any diet restrictions with the risk of malnutrition in Crohn’s.
“Unless a urologist recommends it, I very rarely advise dietary restrictions,” says Bickston.
If you don’t know which type of stone is forming, the best diet changes are also unknown, says Bickston. “[Also] many patients’ food choices may already be limited by their symptoms, and we promote as diverse and healthy a diet as possible.” When in doubt, you can ask your doctor or registered dietitian for individualized dietary recommendations.
3. Eat Calcium-Rich Foods
Although some kidney stones have “calcium” in their name, if you get enough of this vital mineral from food it can actually decrease your risk.
“It may seem counterintuitive, but a low calcium diet can actually increase absorption of oxalate in the intestines, sending more [oxalate] to the kidneys to excrete,” says Jirik, who recommends aiming for the normal recommended daily intake of calcium.
One way to get the calcium you need — the daily value is 1,000 milligrams (mg) for adults ages 19 to 50, and 1,200 mg for women over 50 and men over 70 — is by eating or drinking two to three servings of dairy per day, ideally alongside any foods that contain oxalate. One dairy serving is equivalent to:
- 1 cup of milk
- 1 oz of cheese
- ¾ cup of yogurt
- 1 cup of kefir
You can also get calcium from kale, soy, and fortified cereals and breads.
For added calcium, your provider may recommend taking calcium citrate supplements.
But taking calcium supplements can increase the risk of kidney stones, so be sure to ask your provider before starting anything new.
4. Avoid Long-Term Antibiotic Treatment
When you take antibiotics for too long, they can leave you vulnerable to kidney stones, says Jirik. For example, the research review mentioned earlier also found that taking ciprofloxacin (Cipro, Cipro XR, Proquin XR) increased the chances of kidney stones in people with IBD.
“Antibiotics not only kill bad bacteria, but can kill useful bacteria such as Oxalobacter formigenes, whose main job is to break down oxalate in the intestines and reduce its absorption,” says Jirik.
While you can’t always control how often or for how long you’ll need antibiotics, research suggests that seeing doctors who stick to prescription guidelines, staying up-to-date on vaccinations, and taking specific probiotic strains recommended by your provider when you’re on such medications may help.
5. Stick Closely to Your Crohn’s Treatment Plan
Another excellent way to prevent kidney stones with Crohn’s disease is to collaborate with your healthcare team to hone your treatment plan, says Jirik. “Work closely with your GI provider to optimize your medical regimen for Crohn’s disease to reduce the inflammation in your GI tract.” Less inflammation means better absorption and hydration, plus less diarrhea, which can all lower your risk of kidney stones, says Jirik.