Fistula formation between the kidney and the colon is a rare occurrence. Colorenal fistulas have been reported after renal cryoablation, calculous pyonephrosis, and renal cell carcinoma. Fistula formation is reported in as many as 35% of patients with Crohn’s disease. Crohn’s-related urinary fistulas may include enterovesical, enteroureteral, rectourethral, urethrocutaneous, and entero-urachal fistulas. Here, we report a rare case of a patient who was found to have a right colorenal fistula intra-operatively out of surprise in the setting of a right nonfunctioning kidney with staghorn calculus planned for right simple nephrectomy with a question on table about the eventual definitive management of the patient.

A 57-year-old nil premorbid male came with a complaint of right flank pain for 6 months. He was found to have a right staghorn calculi of size 46x34mm on CT Urography, with a right shrunken nonfunctioning kidney on DTPA scan. No history of previous pyelonephritis or hospital admission. No history of Loss of weight or altered bowel habits. Hence, the patient was planned for laparoscopic simple nephrectomy.

Intraoperatively, due to peri-nephric adhesion, it was converted to an open right flak incision, and to our surprise, a large Colo-renal fistula was noted between the renal pelvis and ascending colon with absent staghorn calculi. Right simple Nephrectomy was done, with primary closure of colonic rent and fistula excision. Postoperatively, the patient gave a history of the recent passage of hard feces 2 days before hospital admission. Later on, the patient also procured the stone that was passed per rectum, which was later sent for stone analysis

Reports of a fistula between the kidney and bowel have been associated with tuberculosis, renal calculi, renal cell carcinoma, Crohn’s disease, and iatrogenic trauma, such as renal cryoablation.1-2 Presenting symptoms of colorenal fistula can range from urinary frequency and dysuria to pneumaturia, flank pain, and hematochezia.3 Management of colorenal fistula can vary from bowel rest to nephrectomy and colectomy3,4. Our patient didn’t have any history of pyelonephritis/Crohn’s/TB. Given the patient’s poor split function of the right kidney, possible options would be a right nephrectomy with general surgery assistance for possible primary closure of colonic rent with or without diverting stoma or colonic resection.