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Pyeloenteric Fistula

A pyeloenteric fistula is a rare abnormal communication between the renal pelvis (pyelo-) and a segment of the gastrointestinal tract (enteric). The most commonly reported subtype is the pyeloduodenal fistula. Fistulae to the colon (pyelocolic or renocolic) are also well described, and some surgical series treat them as the most frequent nephroenteric fistula.[1][2][14] It is the upper-tract counterpart to the more familiar enterovesical fistulas of the bladder, and often arises from chronic infected obstruction or calculus disease; traumatic, iatrogenic and malignant causes also occur.[13]

For operative selection, see the Fistula Repair (All Patients) database.

See also: The Kidneys, Fistulas landing page.

Definition and Classification​

A pyeloenteric fistula falls under the broader category of uroenteric fistulae, which are classified by the urinary-tract organ of origin and the GI-tract segment involved.[1] Specific subtypes include:

  • Pyeloduodenal fistula — the most frequently reported form; in the 2000–2023 literature every spontaneous case involved the right kidney, because of its proximity to the second portion of the duodenum[2][3][13]
  • Renocolic / pyelocolonic fistula — communication between the kidney and colon; reported with chronic obstructive stone disease and pyonephrosis, xanthogranulomatous pyelonephritis, renal tuberculosis, trauma and renal tumor ablation, and treated with nephrectomy plus resection of the involved colon in the reported cases[14][15][16][17]
  • Pyeloileal or other small-bowel fistulae — exceedingly rare

Congenital fistulae are extremely rare; the vast majority are acquired.[1]

Etiology​

The fistula most commonly arises from a chronic inflammatory process originating in the kidney:[2][3]

  • Renal calculi with chronic pyelonephritis — the most frequent cause; calculi were present in 81% and pyonephrosis in 76% of the 25 pyeloduodenal cases in the 2000–2023 literature.[13] Staghorn calculi and recurrent infections drive perirenal abscess formation that erodes into adjacent bowel[2][3][4]
  • Renal or perirenal abscess — can erode through Gerota's fascia into the duodenum or colon[5]
  • Iatrogenic / traumatic — described after percutaneous nephrolithotomy (PCNL), renal trauma and thermal ablation of renal tumors. Traumatic cases were 4 of 25 (15%) in the 2000–2023 review, so this is a minority mechanism.[5][13][14][16]
  • Malignancy — rare; reported with renal cell carcinoma and transitional cell carcinoma of the renal pelvis[6]
  • Inflammatory bowel disease — Crohn's disease can produce urinary fistulas; the cited Crohn cohort predominantly involved the bladder, not the renal pelvis[1][7]
  • Xanthogranulomatous pyelonephritis — destructive granulomatous process that can extend beyond the kidney into adjacent viscera; renocolic fistula is a reported complication[17]
  • Renal tuberculosis — reported as the underlying cause of a renocolic fistula found only on histology after nephrectomy with colectomy[15]

Pathogenesis​

The typical sequence is chronic renal infection or obstruction (most often from calculi) → perirenal inflammation and abscess → erosion through Gerota's fascia and the peritoneum → fistulization into the adjacent bowel wall. The right kidney's intimate relationship to the second portion of the duodenum explains the strong right-sided predominance of pyeloduodenal fistulae.[2][3]

Clinical Presentation​

Symptoms are nonspecific and overlap with those of the underlying renal disease, which makes the diagnosis easy to miss:

  • Fever, often recurrent or persistent (67% of the 25 recent pyeloduodenal cases)[13]
  • Flank pain and abdominal discomfort (57%)[13]
  • Recurrent urinary tract infections or urosepsis[8]
  • Gastrointestinal symptoms — nausea, vomiting, diarrhea
  • Pneumaturia or fecaluria — the hallmark of enterovesical fistulae and uncommon with a pyeloenteric tract; when present with a renocolic fistula they suggest a wide communication. Pyuria is expected with the underlying infected obstruction and is not specific
  • Hematuria
  • Reported passage of urinary calculi per rectum — an unusual clue requiring imaging confirmation; nonspecific debris is not diagnostic
  • Anemia and weight loss in chronic cases[4]
  • Sepsis — a renocolic fistula has presented with septicemia and organ dysfunction[15]

Evaluation​

The diagnosis is frequently incidental, made during imaging or procedures performed for the underlying renal disease.[4][8]

ModalityRole
CT abdomen / pelvis with contrastIncreasingly the primary diagnostic tool; CT urography or antegrade pyelography made the diagnosis in about 80% of the recent pyeloduodenal cases;[13] demonstrates the fistulous tract, perinephric inflammation, gas in the collecting system, and associated calculi or abscess[4][9]
Retrograde pyelographyHistorically the most effective study for demonstrating the tract[3]
Antegrade pyelography / nephrostographyContrast injection through a percutaneous nephrostomy tube can opacify the bowel and confirm the fistula[4][8]
Upper GI series / barium studiesMay show contrast entering the collecting system. Barium enema helped define a renocolic fistula[15]
FistulographyUseful for follow-up and confirmation of closure[8]
CystoscopyMore relevant for lower-tract uroenteric fistulae[7]

Management​

Management depends on the underlying etiology, the patient's overall condition, and the complexity of the fistula.[1][10]

Surgical management​

  • Nephrectomy with closure of the bowel defect is frequently used for a nonfunctioning, severely infected kidney. Assess residual renal function, source control and the possibility of renal preservation before choosing an ablative operation[2][3][4]
  • A multidisciplinary approach with urology and GI / colorectal surgery is recommended for complex cases[10]
  • For complex entero-urinary fistulae, a staged approach has been described: (1) proximal defunctioning and drainage to control sepsis, (2) nutritional optimization with TPN, and (3) delayed definitive reconstruction once the patient is stable[10]

Conservative and minimally invasive alternatives​

  • Ureteral stenting (internal or percutaneous) was proposed as an alternative to nephrectomy in a two-case report with literature review, by diverting urine and allowing the tract to heal[11]
  • Endoscopic clipping and ligation — successful closure of a pyeloduodenal fistula using endoclips and an endoloop has been reported in a patient unfit for surgery[8]
  • Percutaneous fulguration of the fistulous tract has been described as a nephron-sparing option[12]
  • Medical management — antibiotics, nutritional support, and treatment of the underlying inflammatory process (for example, immunosuppressants for Crohn's disease) may be attempted, though durable success without surgery is uncommon[1][7]

Key principles​

Adequate nutrition, eradication of sepsis, urinary-tract diversion, GI-tract diversion when needed, and treatment of the underlying cause anchor the management plan.[1]

Outcomes​

The historical 28-case review supported nephrectomy with duodenal closure for severely diseased kidneys.[3] A 2025 review identified 25 cases from 24 reports published in 2000–2023; more than half underwent nephrectomy. These uncontrolled reports describe management choices and cannot establish comparative superiority, a reliable recurrence rate, or a universal requirement for nephrectomy.[13] Nephrectomy was accompanied by parenteral nutrition in 28% of these cases, and the review's authors describe duodenal closure with somatostatin and parenteral nutrition as the most frequent approach.[13] No mortality rate can be derived from these reports. A separate 10-patient series reported successful staged treatment of mixed complex entero-urinary fistulas, not ten pyeloduodenal fistulas; all ten were closed or diverted with no postoperative deaths, at a mean of 5 months to reconstruction, in patients referred to a national intestinal failure unit.[10] Case reports also describe endoscopic clipping in a patient unfit for surgery, percutaneous fulguration (no recurrence on imaging at 18 weeks), and nephrectomy with bowel resection for colonic fistulas; each is a single case.[8][12][14]

See Also​

References​

1. Gill HS. "Diagnosis and Surgical Management of Uroenteric Fistula." Surg Clin North Am. 2016;96(3):583–592. doi:10.1016/j.suc.2016.02.012

2. Greene JE, Bucy JG, Wise L. "Spontaneous Pyeloduodenal and Renocolic Fistulas." South Med J. 1975;68(5):641–645. doi:10.1097/00007611-197505000-00029

3. Rodney K, Maxted WC, Pahira JJ. "Pyeloduodenal Fistula." Urology. 1983;22(5):536–539. doi:10.1016/0090-4295(83)90237-6

4. Gentile PA, Gualtieri L, Izzo S, et al. "Une Liaison Dangereuse: Spontaneous Pyeloduodenal Fistula." Dig Dis Sci. 2023;68(4):1106–1111. doi:10.1007/s10620-023-07828-1

5. Wang JH, Chiang JH, Chang T, Chen KK. "Pyeloduodenal Fistula: Report of 2 Cases." J Formos Med Assoc. 1990;89(12):1111–1114.

6. Chen CH, Cheng HL, Tong YC, Pan CC. "Spontaneous Pyeloduodenal Fistula: An Unusual Presentation in Advanced Renal Transitional Cell Carcinoma." Urology. 2002;60(2):345. doi:10.1016/s0090-4295(02)01749-1

7. Solem CA, Loftus EV, Tremaine WJ, et al. "Fistulas to the Urinary System in Crohn's Disease: Clinical Features and Outcomes." Am J Gastroenterol. 2002;97(9):2300–2305. doi:10.1111/j.1572-0241.2002.05983.x

8. Lee KN, Hwang IH, Shin MJ, et al. "Pyeloduodenal Fistula Successfully Treated by Endoscopic Ligation Without Surgical Nephrectomy: Case Report." J Korean Med Sci. 2014;29(1):141–144. doi:10.3346/jkms.2014.29.1.141

9. Yu NC, Raman SS, Patel M, Barbaric Z. "Fistulas of the Genitourinary Tract: A Radiologic Review." Radiographics. 2004;24(5):1331–1352. doi:10.1148/rg.245035219

10. Shackley DC, Brew CJ, Bryden AA, et al. "The Staged Management of Complex Entero-Urinary Fistulae." BJU Int. 2000;86(6):624–629. doi:10.1046/j.1464-410x.2000.00871.x

11. Desmond JM, Evans SE, Couch A, Morewood DJ. "Pyeloduodenal Fistulae: A Report of Two Cases and Review of the Literature." Clin Radiol. 1989;40(3):267–270. doi:10.1016/s0009-9260(89)80194-1

12. Kim SC, Weiser AC, Nadler RB. "Nephroenteric Fistula Treated With Fulguration of the Fistulous Tract." J Endourol. 2000;14(5):443–445. doi:10.1089/end.2000.14.443

13. Spanggaard K, Hvid NK, Diatchikhine M, Olesen TH, Lund L. "Pyeloduodenal Fistula: A Review of the Current Literature." Int Urol Nephrol. 2025;57(5):1357–1363. doi:10.1007/s11255-024-04327-8

14. Campobasso D, Granelli P, Maestroni U, et al. "Are Nephroenteric Fistulas Only a Surgical Trouble?" Indian J Surg. 2015;77(3):222-5. doi:10.1007/s12262-014-1046-1

15. Marwah S, Garg S, Marwah N, et al. "Tubercular renocolic fistula: an unusual presentation." Clin J Gastroenterol. 2012;5(5):347-50. doi:10.1007/s12328-012-0324-3

16. Sáenz Medina J, Redondo González E, Hernández-Atance JM, et al. "Renocolic fistula as a complication of radiofrequency in the treatment of renal cell carcinoma." Arch Esp Urol. 2010;63(1):74-7. PMID 20157223

17. Numan L, Zamir H, Husainat NM, et al. "Xanthogranulomatous Pyelonephritis Causing Renocolic Fistula Presenting as Symptomatic Anemia." Cureus. 2019;11(6):e4947. doi:10.7759/cureus.4947