Crohn’s disease is a chronic inflammatory bowel disease (IBD) that primarily affects the gastrointestinal (GI) tract. While the focus is often on intestinal symptoms like abdominal pain, diarrhea, and weight loss, Crohn’s disease can also impact other organs, including the kidneys. Here, we'll go over some important information regarding the connection between Crohn's disease and kidney health, along with when to see your doctor.
What Is Crohn’s Disease?
Crohn’s disease is an autoimmune IBD where the immune system mistakenly attacks the lining of the gastrointestinal tract, causing inflammation. This inflammation can occur anywhere from the mouth to the anus, but it most commonly affects the small intestine (specifically the ileum) and the colon.
Symptoms can come and go, with periods of active disease (flare-ups) followed by periods of remission. The symptoms can also range from mild to severe, and may be triggered by diet, stress, changes in medication, smoking, infections, hormonal changes, poor sleep, fatigue, and more. Some of the most common symptoms of Crohn's disease include:
- Abdominal pain
- Cramping
- Diarrhea
- Fatigue
- Weight loss
- Reduced appetite
- Fever
- Mouth sores
- Bowel obstruction
- Malnutrition
- Fistulas
- Anal fissures
Unfortunately, the exact cause of Crohn's disease is unknown, but genetics, environment, and immune system dysfunction all seem to play a role. If you start to experience any symptoms and have not been diagnosed, it's important to schedule an appointment with your doctor as soon as possible. While there are treatments available, Crohn's disease surgery may be the best way to reduce the risk of ongoing symptoms and further complications.
What is Inflammatory Bowel Disease?
Inflammatory bowel disease is a term used to describe chronic conditions that cause inflammation in the digestive tract. There are two main types: Crohn's disease and ulcerative colitis. Crohn's disease can affect any part of the GI tract, while ulcerative colitis typically only affects the colon and rectum. However, any type of IBD can increase the risk of CKD.
How Crohn’s Disease Can Affect Kidney Health
Crohn's disease is considered a systemic disease that can affect multiple organs or systems within the body. Rather than a localized condition, this means that people with Crohn's disease are at an increased risk for chronic kidney disease, among other things. But what is the relationship between the two, and why does IBD increase the risk for CKD? Here are a few potential explanations.
1. Dehydration from Chronic Diarrhea
Frequent diarrhea is one of the hallmark symptoms of Crohn’s disease, which can lead to dehydration. Without proper fluid intake to make up for the loss, dehydration can reduce blood flow to the kidneys and impair their function. Over time, chronic dehydration can also increase the risk of kidney stones and acute kidney injury (AKI).
2. Malabsorption of Key Nutrients
Crohn’s disease can also interfere with the absorption of essential nutrients like calcium and magnesium. Low calcium levels, especially when paired with high oxalate levels (often seen in patients with fat malabsorption), can lead to calcium oxalate kidney stones, which are the most common type of kidney stone.
3. Medications and Nephrotoxicity
Some medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), can impair kidney function and may even worsen Crohn's symptoms. Additionally, immunosuppressants like cyclosporine or tacrolimus can negatively impact kidney function and increase the risk of injury. Aminosalicylates (e.g., mesalamine) are also associated with rare but serious kidney side effects such as interstitial nephritis.
4. Chronic Inflammation
Chronic systemic inflammation is a central feature of Crohn’s disease and may contribute to kidney damage over time. Inflammatory cytokines can affect kidney tissue directly and indirectly by damaging blood vessels or causing scarring.
5. Urinary Complications from Fistulas
In some cases, Crohn’s can cause abnormal connections (fistulas) between the intestine and other organs, including the bladder or ureters. This can lead to recurrent urinary tract infections (UTIs) or kidney infections (pyelonephritis).
6. Secondary Amyloidosis
This rare but serious complication can occur in patients with long-standing, poorly controlled Crohn’s. Chronic inflammation causes abnormal protein (amyloid) accumulation in organs, including the kidneys, leading to nephrotic syndrome or chronic kidney disease.
Common Kidney-Related Conditions in Crohn’s Patients
While the true relationship between IBD and kidney health is still unknown, some researchers believe that it could be a result of the ongoing inflammation, medication necessary to treat Crohn's and colitis, or even metabolic disorders that are related to IBD. Still, there are a few distinct kidney problems that individuals need to be aware of when living with either type of irritable bowel disease. These include:
Kidney Stones
One study found that individuals with Crohn's disease and kidney stones had a 10-fold higher risk of developing CKD than those without kidney stones. Stones seem to be the most common complication of IBD, which may be a result of malabsorption issues. Many people with Crohn's disease in the small intestine can't absorb fat properly, which can cause oxalate stones to form. When paired with dehydration from diarrhea or other risk factors, this can further increase prevalence. If you experience any symptoms of kidney stones, it's important to see your doctor for treatment. While some stones can be passed at home, larger ones may require surgery or endoscopic removal.
Chronic Kidney Disease
Chronic kidney disease is a progressive decline in kidney function, often linked to long-term inflammation. In a recent study, researchers found that a diagnosis of CKD was about three times more common among patients with Crohn's disease than ulcerative colitis. In this study, the criteria for a diagnosis of CKD were an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 for ≥ three months apart, or those with a history of end-stage renal disease requiring a kidney transplant. The risk further increased in patients who had kidney stones and previous intestinal resections.
Acute Kidney Injury (AKI)
AKI is the sudden loss of kidney function, often due to dehydration or nephrotoxic drugs. One study found that patients with inflammatory bowel disease had a 96% increased risk of acute kidney injury compared to patients with diseases other than IBD. This may be because IBD often leads to salt and water loss due to persistent inflammation, diarrhea, and surgeries, but more information is needed.
Signs and Symptoms to Watch For
Because kidney problems can develop quietly, individuals with Crohn’s disease need to watch for signs and see a doctor if symptoms are present. Severe damage to the kidneys can't be repaired, which is why early intervention is so important. Some of the most notable signs of kidney issues include:
- Weight loss
- Pale skin
- Anemia
- Feeling unwell
- Swelling in the legs or ankles
- Swelling in the hands
- Headaches
- Shortness of breath
- High blood pressure
- Increased need to urinate
- Blood in urine
- Foamy or dark-colored urine
- Changes in urination frequency
- Flank or lower back pain
- Difficulty sleeping
- Erectile dysfunction
If any of these symptoms appear, it's important to see your doctor for a medical evaluation.
How to Protect Kidney Health When Living With Crohn’s
Although it can be challenging to completely avoid kidney problems with Crohn's disease, there are some things that you can do to help reduce your risk. These include:
- Drink enough fluids to flush the kidneys and prevent kidney stone formation
- Undergoing routine blood work
- Getting a regular urinalysis
- Avoid over-the-counter NSAIDs unless approved by your doctor
- Try to reduce systemic inflammation with lifestyle changes
- Keep an eye on your diet
- Limit oxalate-rich foods (spinach, nuts, chocolate)
- Increase calcium intake
- Regularly check for magnesium, calcium, and vitamin D deficiencies
When to See Your Doctor
If you're living with Crohn's disease or ulcerative colitis, it's important to schedule regular check-ins with your doctor to monitor your health. However, if you begin experiencing any signs or symptoms that could indicate a kidney problem, schedule an appointment as soon as possible. Your doctor may refer you to a kidney specialist (nephrologist) to get a better picture of what's going on and the best course of action. Remember, early detection can prevent further progression of CKD and allow for early interventions. This is the best way to ensure that you maintain a healthy kidney function over the years.
Luckily, with routine monitoring and strategic medication choices, many kidney-related complications of Crohn's can be avoided or managed. So, if you're living with Crohn's disease, don't forget that your kidneys are also important to monitor. And, over the years, if your doctor recommends an ostomy to alleviate flare-ups and help reduce the risk of additional complications, Byram Healthcare is here. Byram Healthcare is committed to supporting individuals living with IBD by providing reliable access to high-quality ostomy supplies, educational resources, and personalized care. Browse our ostomy product catalog today or contact us to get started.
