Renal Manifestations in Inflammatory Bowel Disease: A Cohort Study During the Biologic Era.

BACKGROUND Renal involvement can complicate the course of inflammatory bowel disease (IBD). In this study, we aimed to analyze the extent of renal manifestations in patients with IBD (Crohn disease or ulcerative colitis) during the biologic era. MATERIAL AND METHODS Patients diagnosed with and followed up for IBD for a period covering 16 years were retrospectively analyzed. Patients who received IBD diagnosis with clinical, endoscopic, and histopathological findings and were older than 18 years were enrolled in the study. Demographic, clinical, laboratory, and treatment data were retrieved from the patients' medical records. RESULTS Of the 1874 patients analyzed, the diagnosis was ulcerative colitis in 1055 patients and Crohn disease in the remaining 819. Renal manifestations were found in 105 patients (5.6%), 55 (6.7%) of whom were diagnosed with Crohn disease and 50 (4.7%) with ulcerative colitis. Renal calculi was the most common renal manifestation for both Crohn disease and ulcerative colitis. Renal manifestations were related to disease activity and surgical resection history in patients with Crohn disease, whereas no such relationship was found in patients with ulcerative colitis. CONCLUSIONS Renal manifestations may be seen in up to 6% of patients with IBD, and patients with Crohn disease seems to have more risk than do patients with ulcerative colitis. Nephrolithiasis is the most common form of renal involvement in IBD and is closely associated with disease activity. This relationship between IBD and renal manifestations should be considered, especially when there are subtle renal symptoms.