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Ureterocolonic Fistula

A ureterocolonic fistula is a rare abnormal communication between the ureter and the colon. It falls within the broader category of uroenteric fistulae and is almost always acquired, arising from inflammatory, iatrogenic, neoplastic, or radiation-related processes.[1][2][3] The left ureter is involved in approximately 75% of cases because of its anatomic proximity to the sigmoid colon.[5]

See also: The Ureters, Fistulas landing page, Pyeloenteric Fistula.

Definition and Classification​

The fistula is classified by the urinary-tract organ of origin (ureter) and the GI segment involved (colon). It is distinct from:

  • Enterovesical fistula (bowel-to-bladder) — the most common uroenteric fistula overall
  • Pyeloenteric fistula (renal pelvis–to–bowel)
  • Ureteroileal fistula (ureter-to-ileum) — exceedingly rare, with fewer than 10 reported cases in the older literature[4]

Etiology​

MechanismNotes
Obstructing ureteral calculiHistorically the most common spontaneous cause. Chronic stone impaction drives periureteral inflammation, abscess, and erosion into the adjacent colon.[2][5][6]
Colonic diverticular diseaseSecond most common spontaneous cause. Recurrent sigmoid diverticulitis erodes into the left ureter; diverticulitis-related cases show a 3:1 female predominance and a mean age of 77 years.[5]
MalignancyColorectal carcinoma, urothelial carcinoma of the ureter, or locally advanced pelvic malignancies producing direct invasion or necrotic fistulization.[1][2]
Inflammatory bowel diseaseCrohn's disease is the dominant cause of uroenteric fistulae overall, but ureteral involvement (~1%) is far less common than vesical involvement (~88%).[7]
Xanthogranulomatous pyelonephritisDestructive granulomatous process can extend along the ureter into adjacent bowel.[8]
Iatrogenic — colorectal / gynecologic surgeryMost common iatrogenic cause; unrecognized intraoperative ureteral injury during colectomy, anterior resection, or hysterectomy. Risk factors: diverticular disease (OR 2.1), T4 malignancy (OR 1.8), prior radiotherapy, re-operative surgery.[1][2][9]
Anastomotic leakColorectal anastomotic leak eroding into the adjacent ureter — reported after laparoscopic anterior resection for sigmoid cancer.[1]
Extracorporeal shock-wave lithotripsyRare; reported at a stone-fragment impaction site after piezoelectric ESWL.[8]
Pelvic radiotherapyDelayed radiation enteropathy with fistulization typically 3 months to 6 years after treatment. Overall prevalence ~0.2%; risk increases with re-irradiation, concurrent chemotherapy, and prior surgery.[10][11]

Pathogenesis​

  • From urologic disease: obstructing calculus → periureteral inflammation and abscess → erosion through the ureteral wall into the adjacent colon
  • From colonic disease: diverticulitis or colonic malignancy → pericolic inflammation → erosion into the adjacent ureter
  • From iatrogenic injury: unrecognized ureteral injury → urine leak → periureteral abscess → fistulization to the bowel anastomosis or adjacent colon[1][2]
  • From radiation: chronic ischemic vasculitis of ureteral and colonic walls → tissue necrosis → delayed fistulization months to years later[10]

Clinical Presentation​

Symptoms are nonspecific and insidious; diagnostic delay of up to 10 years has been reported.[5][12] Urologic symptoms tend to dominate over GI symptoms:

  • Recurrent urinary tract infections — present in 100% of cases in one diverticulitis review[5]
  • Fecaluria — 75%[5]
  • Abdominal pain — 75%[5]
  • Flank pain — 50%[5]
  • Pneumaturia — passage of gas during urination
  • Watery diarrhea — may be the presenting symptom in iatrogenic cases as urine drains into the colon[1]
  • Fever, particularly in the postoperative setting[1]
  • Hematuria
  • Progressive ipsilateral renal-function loss from chronic obstruction and infection[2]

Evaluation​

The correct diagnosis is established preoperatively in approximately 75% of cases.[5]

Imaging​

ModalityRole
CT urography (nephrographic + 5–20-min excretory phase)Gold standard; demonstrates contrast extravasation from ureter into colon, periureteral inflammation, hydronephrosis, calculi, or abscess.[9][13]
Retrograde pyelography / ureterographyDirect demonstration of contrast flowing from ureter into colon; detection rate ~25% in older series.[5]
Antegrade nephrostogramContrast injection through a percutaneous nephrostomy can opacify the fistula and confirm the communication.[6]
Barium enemaHistorically the most reliable single test (75% detection vs. 33% for IVP and 25% for retrograde pyelography); avoid in the acute diverticulitis setting because of perforation risk.[5][14]
CT colonographyEmerging modality with potential utility in colonic fistulae.[15]
Intravenous pyelogram (IVP)Shows hydronephrosis and obstruction; low sensitivity (~33%) for the fistula itself.[5]

Other diagnostics​

  • Cystoscopy — efflux of turbid or feculent urine from the affected ureteral orifice
  • Colonoscopy — may identify the colonic opening or the underlying pathology (diverticulitis, malignancy)
  • Renal scintigraphy (DMSA / MAG3) — quantifies differential function of the affected kidney and drives the kidney-salvage vs. nephroureterectomy decision[2]

Management​

Treatment depends on etiology, timing of diagnosis, residual renal function on the affected side, and the patient's overall condition.[3][16]

General principles[3][16]​

  1. Adequate nutrition (TPN if needed)
  2. Eradication of sepsis
  3. Urinary-tract diversion
  4. GI-tract diversion when necessary
  5. Treatment of the underlying cause
  6. Definitive surgical reconstruction once the patient is optimized

Conservative / minimally invasive management​

Best suited to early-diagnosis iatrogenic fistulae.

  • Percutaneous nephrostomy + antegrade ureteral stenting — diverts urine and allows spontaneous closure. In a 50-patient series of ureteral fistulae, percutaneous stenting achieved a 60% salvage rate of renal function with far less morbidity than open repair. A ureterocolonic fistula from urolithiasis has been managed successfully with antegrade stent placement alone.[17][6]
  • Retrograde ureteral stenting — alternative when the fistula can be traversed cystoscopically; the American College of Surgeons recommends retrograde stenting or PCN for delayed-presentation ureteral injuries.[18]
  • Combined endoscopic and percutaneous management — successful nonoperative resolution of a ureterocolonic fistula after anterior resection for sigmoid cancer when diagnosed and treated early.[1]
  • Percutaneous management of upper-tract fistulae has achieved healing in 70% (28/40) in one series, with the highest success rates for post-endourologic (9/9) and post-ureterointestinal-anastomotic (7/8) fistulae.[19]

Definitive surgical management​

Required for most spontaneous fistulae and for complex or refractory iatrogenic cases.

  • Bowel resection with primary anastomosis — standard when the fistula is driven by colonic pathology (diverticulitis, malignancy). Manipulation of the urinary system is generally unnecessary unless the kidney is nonfunctional.[5]

  • Nephroureterectomy — when the affected kidney has lost significant function from chronic obstruction and infection.[2][12]

  • Ureteral repair — when the kidney is salvageable, reconstruction depends on the location and length of the defect:[9][18]

  • Staged management for complex entero-urinary fistulae — three phases:[16]

    1. Acute: proximal defunctioning and distal drainage of both GI and urinary tracts; eradication of sepsis
    2. Recovery: TPN, organ support, radiologic planning
    3. Reconstructive: joint urologic and GI surgical repair once nutritionally replete and stable

    This approach achieved 100% success with no postoperative deaths in 10 patients, with a mean time to definitive reconstruction of 5 months (range 1–20 months).[16]

  • Radiation-induced fistulae — particularly difficult because of poor tissue vascularity. Conservative management is generally ineffective for large fistulae, and most patients require urinary and / or fecal diversion for symptomatic resolution.[20][10]

Prevention​

For iatrogenic ureterocolonic fistula during colorectal and pelvic surgery:

  • Prophylactic ureteral stent placement — utilization rose from 6.7% to 16.3% between 2000 and 2013 for colectomies. The American Society of Colon and Rectal Surgeons recommends placement "at the discretion of the surgeon," with stronger justification for morbid obesity, prior radiation, abnormal anatomy, and re-operative surgery.[9]
  • Careful surgical technique — particularly during dissection between Toldt's and Gerota's fascia and during ligation of the inferior mesenteric vessels, the highest-risk phases for ureteral injury.[9]
  • Intraoperative ureteral identification — direct inspection, methylene blue, or cystoscopic visualization of ureteral efflux when injury is suspected.[18]

Outcomes​

  • Surgical outcomes are excellent — 100% cure in the diverticulitis-related ureterocolonic fistula review.[5]
  • Early diagnosis of iatrogenic fistulae allows successful conservative management without reoperation.[1]
  • Delayed diagnosis (months to years) drives progressive renal-function loss and may necessitate nephroureterectomy.[2][12]
  • Radiation-induced fistulae carry the worst prognosis and often require permanent diversion.[20]

References​

1. Tramontano S, Iacone B, Parrella V, et al. "Case Report: Unusual Presentation and Atypical Course of a Case of Ureterocolic Fistula After Anterior Resection for Sigmoid Cancer." Front Oncol. 2025;15:1549485. doi:10.3389/fonc.2025.1549485

2. Omar H, Fulaij AA, Felemban J, et al. "Iatrogenic Ureterocolic Fistula in Pediatric Age Group: A Case Report and Review of the Literature." Urology. 2023;173:e1–e5. doi:10.1016/j.urology.2023.01.005

3. 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

4. Nieh PT. "Ureteroileal Fistulas." J Urol. 1983;130(3):555–557. doi:10.1016/s0022-5347(17)51302-6

5. Cirocco WC, Priolo SR, Golub RW. "Spontaneous Ureterocolic Fistula: A Rare Complication of Colonic Diverticular Disease." Am Surg. 1994;60(11):832–835.

6. Lee WK, Chang SD, Roche CJ, et al. "Spontaneous Ureterocolic Fistula Secondary to Calculous Pyohydroureteronephrosis." Br J Radiol. 2005;78(934):954–955. doi:10.1259/bjr/53711174

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. Flood HD, Jones B, Grainger R. "Ureterocolic Fistula: A Unique Complication of Extracorporeal Shock Wave Lithotripsy." J Urol. 1992;147(1):122–124. doi:10.1016/s0022-5347(17)37154-9

9. de'Angelis N, Schena CA, Marchegiani F, et al. "2023 WSES Guidelines for the Prevention, Detection, and Management of Iatrogenic Urinary Tract Injuries (IUTIs) During Emergency Digestive Surgery." World J Emerg Surg. 2023;18(1):45. doi:10.1186/s13017-023-00513-8

10. Turina M, Mulhall AM, Mahid SS, Yashar C, Galandiuk S. "Frequency and Surgical Management of Chronic Complications Related to Pelvic Radiation." Arch Surg. 2008;143(1):46–52; discussion 52. doi:10.1001/archsurg.2007.7

11. Sadighian M, Hakam N, Amend G, et al. "Radiation-Induced Fistulas in Patients With Prior Pelvic Radiotherapy for Prostate Cancer: A Systematic Review and Meta-Analysis." Urology. 2023;176:121–126. doi:10.1016/j.urology.2023.03.015

12. Maeda Y, Nakashima S, Misaki T. "Ureterocolic Fistula Secondary to Colonic Diverticulitis." Int J Urol. 1998;5(6):610–612. doi:10.1111/j.1442-2042.1998.tb00422.x

13. 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

14. Brown RF, Lopez K, Smith CB, Charles A. "Diverticulitis." JAMA. 2025. doi:10.1001/jama.2025.10234

15. Flor N, Scolari S, Liedenbaum M, et al. "Colonic Acquired Fistulae: The Potential of CT Colonography." Acad Radiol. 2023;30(5):959–965. doi:10.1016/j.acra.2022.07.006

16. 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

17. Lang EK. "Antegrade Ureteral Stenting for Dehiscence, Strictures, and Fistulae." AJR Am J Roentgenol. 1984;143(4):795–801. doi:10.2214/ajr.143.4.795

18. Johnsen N, Wessells H, Archer-Arroyo K, et al. "Best Practices Guidelines: Management of Genitourinary Injuries." American College of Surgeons. 2025.

19. Maillet PJ, Pelle-Francoz D, Leriche A, Leclercq R, Demiaux C. "Fistulas of the Upper Urinary Tract: Percutaneous Management." J Urol. 1987;138(6):1382–1385. doi:10.1016/s0022-5347(17)43648-2

20. Chrouser KL, Leibovich BC, Sweat SD, et al. "Urinary Fistulas Following External Radiation or Permanent Brachytherapy for the Treatment of Prostate Cancer." J Urol. 2005;173(6):1953–1957. doi:10.1097/01.ju.0000158041.77063.ff