Inflamm Bowel Dis. 2023 Aug 1;29(8):1306-1316. doi: 10.1093/ibd/izac140.

Shankar Kumar ¹, Richard Pollok ², David Goldsmith ³

Author information

¹Centre for Medical Imaging, University College London, 2nd Floor Charles Bell House, 43-45 Foley Street, W1W 7TS, London, UK.

²Department of Gastroenterology, St George's University Hospitals NHS Foundation Trust, Blackshaw Road, London, SW17 0QT, UK.

³Renal and Transplantation Department, Guys and St Thomas' Hospitals NHS Foundation Trust, Great Maze Pond, London SE1 9RT, UK.

Abstract

Renal and urinary tract complications related to inflammatory bowel disease (IBD) have been relatively understudied in the literature compared with other extraintestinal manifestations. Presentation of these renal manifestations can be subtle, and their detection is complicated by a lack of clarity regarding the optimal screening and routine monitoring of renal function in IBD patients. Urolithiasis is the most common manifestation. Penetrating Crohn's disease involving the genitourinary system as an extraintestinal complication is rare but associated with considerable morbidity. Some biologic agents used to treat IBD have been implicated in progressive renal impairment, although differentiating between drug-related side effects and deteriorating kidney function due to extraintestinal manifestations can be challenging. The most common findings on renal biopsy of IBD patients with renal injury are tubulointerstitial nephritis and IgA nephropathy, the former also being associated with drug-induced nephrotoxicity related to IBD medication. Amyloidosis, albeit rare, must be diagnosed early to reduce the chance of progression to renal failure. In this review, we evaluate the key literature relating to renal and urological involvement in IBD and emphasize the high index of suspicion required for the prompt diagnosis and treatment of these manifestations and complications, considering the potential severity and implications of acute or chronic loss of renal function. We also provide suggestions for future research priorities.