An unexpected uro-digestive connection: pyelosigmoid fistula in an ectopic pelvic kidney

Pyelo-digestive fistulas are exceptional clinical entities. We report an extremely rare communication between the renal pelvis of an ectopic pelvic kidney and the sigmoid colon, representing only the second such case documented in the global literature. A 45-year-old male presented with recurrent urinary tract infections and abdominal pain. Excretory-phase computed tomography revealed a left pelvic ectopic kidney with pneumopyelia and a direct fistulous tract to the sigmoid colon. A multidisciplinary approach was performed, consisting of a segmental sigmoid resection with primary anastomosis, combined with a conservative reduction pyeloplasty. Postoperative recovery was uneventful, and the 12-month follow-up showed no recurrence. Unlike classic pyelo-colic fistulas, pelvic ectopy facilitates direct contact with the sigmoid colon due to altered anatomical relationships. This case demonstrates that conservative multidisciplinary surgery is a viable alternative to radical nephrectomy when renal function is preserved. Awareness of this variant is essential to avoid diagnostic pitfalls.