Rectovesical Fistula Caused by a Self‐Inserted Intravesical Foreign Body Immobilized by a Giant Vesical Calculus: A Case Report

Introduction Intravesical foreign bodies may remain silent until secondary complications occur. Rectovesical fistula caused by an intravesical foreign body is rare. Case Presentation A 69‐year‐old man presented with urinary frequency and abdominal distension. Computed tomography revealed a 70.8‐mm vesical calculus encasing an approximately 8‐cm plastic object, with bilateral hydroureteronephrosis and suspected rectal involvement. Cystoscopic evaluation was limited by the massive calculus. Intravesical indigo carmine appeared from the rectum, and colonoscopy confirmed a foreign body protruding through the anterior rectal wall. Open cystotomy with removal of the foreign body and fragmented adherent stone, suprapubic cystostomy, and diverting transverse colostomy were performed. Delayed laparoscopic fistula closure and subsequent stoma closure were completed. Hydroureteronephrosis and renal function improved, with no recurrence. Conclusion A long‐retained intravesical foreign body can cause rectovesical fistula through stone‐mediated fixation. Staged management may be appropriate when inflammation and contamination preclude immediate closure.