A review of urinary fistulae in Crohn's disease

Introduction: Urinary fistulae develop as abnormal connections between the gastrointestinal (GI) and genitourinary (GU) tracts, and occur in multiple disease processes including diverticulitis, malignancy, and Crohn's disease. Crohn's disease is now the most common cause of fistula formation between the ileum and bladder and the third most common cause of fistulae between the colon and the bladder. Few articles provide a comprehensive review of this process. Materials and methods: We performed a PubMed search using such terms as "fistula" and "Crohn's disease" and/or "enterovesical fistula." We reviewed references from selected papers and relevant articles were used for information-gathering and cited accordingly. Results: Fistulae in Crohn's disease generally occur due to preformed abscess formation or bowel perforation from the development of aphthous ulcers. The most common type of urinary fistula is enterovesical, due to the close proximity of the ileum and bladder dome. Computed tomography and cystoscopy are the most common diagnostic tools utilized. Surgical treatment is usually definitive; however medical treatment has been used with some success as well. Conclusion: Urinary fistulae represent an uncommon, yet serious problem to patients with Crohn's disease. Patient symptoms and imaging direct the practitioner to proper diagnosis, with direct visualization via cystoscopy confirming the presence of a urinary fistula. Treatment is aimed at relieving symptoms and may be medical or surgical depending on the clinical presentation.