Based on PubMed | Can Crohn's disease cause blood in urine?

Blood in urine (hematuria) is not a typical direct symptom of Crohn’s disease, but it can occur indirectly from certain complications associated with Crohn’s. The most common Crohn’s symptoms involve the digestive tract (like diarrhea, abdominal pain, and blood in stool), not the urinary tract. ^[1] Hematuria in someone with Crohn’s usually suggests a secondary issue such as an abnormal connection (fistula) between bowel and bladder, urinary tract infections, or kidney stones conditions that can be linked to Crohn’s disease in some cases. ^{[2] [3]}

How Crohn’s Could Lead to Blood in Urine

• Enterovesical fistula (bowel-to-bladder connection): Crohn’s inflammation can create ulcers that tunnel into nearby organs, including the bladder, forming a fistula. When a fistula connects the intestine to the bladder, urinary symptoms can appear rarely including hematuria. ^[4] In clinical series, enterovesical fistulas occur in a small percentage of Crohn’s patients (about 2–3%), and only a minority show urinary symptoms; among those, pneumaturia (air in urine) is most common, with hematuria reported in a few cases. ^[5] These fistulas are often difficult to see on routine imaging, and cystoscopy or CT can help; management may require surgical repair, tailored to the involved bowel and bladder segments. ^{[3] [6]}

• Urinary tract infection (UTI) from fistula or altered anatomy: Fistulas or chronic inflammation can predispose to recurrent UTIs, which can cause visible or microscopic blood in urine along with burning, urgency, and foul-smelling urine. ^[5] UTIs are a well‑recognized cause of hematuria in the general population. ^[7]

• Kidney stones (nephrolithiasis) associated with IBD: People with inflammatory bowel disease, including Crohn’s, have a higher risk of kidney stones, often calcium oxalate, due to changes in gut absorption (like increased oxalate absorption during fat malabsorption), dehydration, and altered urine composition. Passing stones commonly causes flank pain and can lead to gross hematuria. ^[8] Prospective community data show kidney stones are relatively common in IBD cohorts, with risks varying by disease pattern and activity; stones may be asymptomatic or present with infections or obstruction. ^[9] Pediatric reports in IBD also document episodes of gross hematuria during stone passage. ^[10]

What Symptoms to Watch For

• Signs suggesting a fistula: Air bubbles in urine (pneumaturia), stool particulate in urine (fecaluria), recurrent UTIs, suprapubic pain, or unexplained urinary symptoms in the setting of active Crohn’s. These signs make an enterovesical fistula more likely. ^{[3] [5]}

• Signs suggesting kidney stones: Sudden flank or lower back pain (often colicky), nausea, painful urination, and pink/red/brown urine. Stones may come and go, and hematuria can be intermittent. ^{[8] [9]}

• Typical Crohn’s symptoms: Diarrhea, abdominal cramps, fatigue, fever, reduced appetite, weight loss, perianal pain/drainage, and blood in stool rather than urine. ^[1]

When to Seek Care

If you have Crohn’s and notice blood in your urine, it’s reasonable to consider urgent evaluation, because hematuria may reflect infections, stones, or a fistula that benefits from prompt management. A clinical exam, urinalysis, urine culture, and targeted imaging (like CT urography or CT abdomen/pelvis) help identify UTIs, stones, or fistulas. ^[3] Persistent urinary symptoms with Crohn’s merit evaluation by gastroenterology and urology working together. ^[6] Definitive management of a fistula often involves surgical resection of the diseased bowel segment and closure of the bladder defect when appropriate, while UTIs are treated with antibiotics and stones with hydration, pain control, and urologic interventions as needed. ^{[5] [11]}

Practical Steps You Can Take

• Document symptoms: Note timing of hematuria, pain location, fever, urinary urgency, pneumaturia, or fecaluria to guide your clinicians. ^[3]
• Hydration and prevention: Adequate fluids can lower kidney stone risk and help prevent UTIs; discuss stone‑risk dietary measures (like moderating oxalate intake) with your care team. ^[8]
• Coordinate care during flares: Active Crohn’s can increase risks of complications; adjusting Crohn’s therapy may reduce downstream urinary issues. ^[2]

Bottom Line

• Crohn’s disease itself does not typically cause blood in urine, but Crohn’s‑related complications especially enterovesical fistulas, UTIs, and kidney stones can lead to hematuria. ^{[2] [3]} If you see blood in your urine and have Crohn’s, it’s important to be evaluated to identify and treat the underlying cause. Most cases are manageable once the specific problem is found. ^[11]