H Dimke et al. Clin Gastroenterol Hepatol 2021; 19: 2532-2540. Risk of Urolithiasis in Patients With Inflammatory Bowel Disease: A Nationwide Danish Cohort Study 1977–2018

Using national registries, the authors identified all patients with IBD (>15 years of age) and all cases of urolithiasis in Denmark during 1977-2018. Key findings:

• 2,549 (3%) of 75,236 IBD patients and 11,258 (2%) of 767,403 non-IBD individuals developed urolithiasis, resulting in a 2-fold increased risk of urolithiasis (HR, 2.27; 95% CI, 2.17-2.38) in patients with IBD
• The authors note that a small risk of urolithiasis preceded the diagnosis of IBD: with OR, 1.42; 95% CI: 1.34-1.50 prior to diagnosis
• After IBD diagnosis, risk of urolithiasis was associated with anti-TNF therapy and surgery (increased disease severity appears to be associated with increased risk). Anti-TNF therapy had a RR of 2.68 in patients with ulcerative colitis and a RR of 3.56 in patients with Crohn’s disease; for surgery, the RR were 3.14 and 2.74 respectively
• One limitation is detection bias as patients with IBD may have more asymptomatic stones identified due to more frequent imaging

My take: This confirms an increased risk of urolithiaiss in patients with IBD and is a good reminder to consider this when patients present with severe abdominal pain/possible flare-up.