Renal and Urological Disorders Associated With Inflammatory Bowel Disease

Lay Summary Renal and urinary tract complications related to inflammatory bowel disease (IBD) are important but have been neglected in the literature. We emphasize the high index of suspicion required for the prompt diagnosis, treatment, and prevention of these manifestations and complications. 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.

Automated summary

Renal and urinary tract complications related to inflammatory bowel disease (IBD) have been neglected in the literature, but are important. Prompt diagnosis and treatment of these manifestations and complications require a high index of suspicion, while optimal screening and monitoring methods for renal function in IBD patients are still unclear. Urolithiasis is the most common manifestation, while penetrating Crohn's disease involving the genitourinary system as an extraintestinal complication is rare but associated with significant 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 other manifestations can be challenging. The most common findings on renal biopsy of IBD patients with renal injury are tubulointerstitial nephritis and IgA nephropathy, with the former also associated with drug-induced nephrotoxicity related to IBD medication. Amyloidosis, though rare, must be diagnosed early to reduce the risk of progression to renal failure. Considering the potential severity and implications of acute or chronic loss of renal function, prompt diagnosis and treatment of these manifestations and complications are crucial.