Colon Conduit Urinary Diversion
A colon conduit is an incontinent diversion in which an isolated colonic segment drains urine from the ureters into an abdominal appliance. Transverse, descending or sigmoid colon is chosen according to tissue quality, vascular supply, ureteral reach and the need for fecal diversion. It is an alternative to the ileal conduit when ileum is unsuitable, and no colonic segment is universally preferred.[1][2]
Selection and segment choice
| Situation | Planning considerations |
|---|---|
| Prior pelvic radiation | Review the actual field and bowel injury. Healthy transverse colon may be available above the treated area |
| Existing or planned colostomy | A suitable colonic segment can provide the urinary conduit with a separate proximal fecal stoma, avoiding an additional bowel-to-bowel anastomosis |
| Limited small-bowel reserve | Preserve remaining absorptive bowel when feasible; assess nutritional status and the effect of excluding colon as well |
| Inflammatory bowel disease or prior colonic surgery | Establish whether the proposed segment and its blood supply are healthy; small-bowel Crohn's disease does not automatically make colon suitable |
| Renal or hepatic impairment | Urine-exposed colon still produces a metabolic burden; assess severity and alternatives |
The historical transverse-conduit literature supports feasibility after radiation but not a comparative reduction in complications.[3][4][2][5]
An isolated colon conduit does not use the anal sphincter for continence. Anal-function prerequisites belong to ureterosigmoidostomy and staged ureterocolocolostomy. Nieh's staged ureterocolocolostomy, for example, lists a poor prognosis, previously irradiated rectosigmoid, fecal incontinence or poor sphincter tone, inflammatory large-bowel disease, inadequate ureteral length and a strong family history of colon cancer as contraindications.[18]
Segments
- Transverse colon has been used after pelvic radiation when a healthy segment lies above the treated field and the ureters can be dissected above irradiated tissue.[3][15] Schmidt described eight patients treated with high-dose external radiotherapy, and Beckley reported satisfactory results in the last 30 patients of a series using an end-to-end (Wallace) refluxing ureterocolic anastomosis.[3][15] The continent counterpart built from nonirradiated transverse colon is the Mainz pouch III.
- Sigmoid and descending colon are used when a colostomy is present or planned. The distal colon becomes the conduit and no bowel anastomosis is needed. Davis described this in 14 patients with preexisting or imminent colostomy, and Alemozaffar reported 41 patients with distal-colon conduits for malignancy, fistula or neurogenic bladder.[6][4] Ligating the hypogastric arteries during cystectomy can compromise rectal blood supply when sigmoid is used for the conduit, and extensive prior pelvic radiation has been described as a reason to avoid the segment; sigmoid can still be considered during total pelvic exenteration because it may avoid an additional intestinal anastomosis. One described technique isolates a 15–20 cm sigmoid segment on a broad inferior-mesenteric-artery pedicle, rotates it 180 degrees clockwise to bring the proximal end toward the ureters, and implants the ureters through a submucosal tunnel along the tenia libera with the seromuscular layer closed loosely over the ureter.[19]
- Children. Hendren described a nonrefluxing colon conduit for temporary or permanent diversion in children.[14]
Operative framework
- Mark stoma sites and select viable bowel with a preserved vascular pedicle. When feasible, have a surgeon or trained ostomy clinician mark the urinary stoma and any planned fecal stoma before surgery, assessing a flat pouching surface while the patient is standing, sitting and supine.[21] The pedicle is the middle colic artery for transverse colon and inferior mesenteric branches for sigmoid or descending colon. Determine the length needed for tension-free ureteral implantation and stoma reach. Prior radiation, scarring, mesenteric injury or active bowel disease may make a proposed segment unsuitable.
- Plan both bowel ends. An isolated segment ordinarily requires restoration of intestinal continuity. When fecal diversion is also required, an appropriately designed proximal colostomy can avoid that bowel-to-bowel anastomosis.
- Preserve ureteral perfusion and avoid tension or angulation. Refluxing implantation can be separate or use a common ureteral plate, so refluxing is not synonymous with Wallace. An end-to-end refluxing ureterocolic anastomosis allows later retrograde conduitography to evaluate the urothelium.[15] A nonrefluxing submucosal tunnel is feasible in the thick colonic wall but requires adequate ureteral caliber and freedom from compression.
- Mature a well-perfused, accessible stoma. Confirm unobstructed drainage and a feasible appliance surface. Coordinate the siting of any fecal stoma.
Theva's five-patient series of sigmoid conduit with end colostomy reported operative times of 5 to 11 hours and one Clavien III complication.[5] See the colon shuffle for colostomy conversion and upper-tract reconstruction principles for ureteral handling.[6][7][5]
The Cochrane review (search to October 2011) included five small trials. One small trial comparing ileal with colonic conduits reported no statistically significant difference in upper urinary tract infection or uretero-intestinal stenosis. Across the included diversion studies, antirefluxing and freely refluxing anastomoses did not show a statistically significant difference in renal scarring, but the data were too limited to exclude important clinical differences. The review concluded that the evidence was insufficient to identify a best technique.[8]
In 1980, Dagen reported two cases of severe stenosis of the ureter within the submucosal tunnel of a nonrefluxing colon conduit and noted that, with long-term follow-up, the incidence was 8 to 10% of patients and might exceed that of refluxing conduits. Techniques described to prevent stenosis are preservation of periureteral adventitia, careful formation and closure of the submucosal tunnel, a tension-free anastomosis, and tapering the ureters adequately but not excessively. Correction may require lysis of adhesions, a refluxing ureterocolic anastomosis, transureteroureterostomy, transureteropyelostomy, ureteral replacement with small bowel or nephroureterectomy.[7]
In Morales's 46 colon conduits (39 transverse, 7 sigmoid), the advantages reported were minimal stomal stenosis, little residual urine, less electrolyte disturbance and availability for high and low diversions. The series moved from widened refluxing anastomoses to antireflux procedures after the dangers of reflux were recognized.[16]
Contemporary outcomes
Hebert's 2026 retrospective study included 179 patients from four institutions, treated during 1990–2022. Prior radiation and abdominal surgery were common; the cohort combined colon conduits with anastomosis, with colostomy and with colostomy switch.[1]
| Outcome | Reported result |
|---|---|
| High-grade complications within 30 days | 28.5% |
| High-grade complications during days 30–90 | 14.5% |
| Mortality within 90 days | 4.5% |
| Reintervention within 90 days | 30.2% |
| Later ureteral stent or nephrostomy requirement | 16.8% |
Source: Hebert 2026.[1] Preoperative albumin ≥3.2 g/dL was associated with fewer 30–90-day high-grade complications (HR 0.18). A high-grade complication within 30 days was associated with a secondary high-grade complication between days 30 and 90 (HR 2.85). In Hebert’s retrospective cohort, concurrent colonic anastomosis was not associated with worse 30-day outcomes.
Comparisons with ileal conduit
Hagemans retrospectively compared 214 ileal and 45 colon conduits after rectal-cancer exenteration. Ileus occurred in 21% versus 7%; wound infection in 14% versus 31%, although the wound association did not persist in adjusted analysis. Nine ileal-conduit patients had an ileo-ileal anastomotic leak.[9] Other selected outcomes were not statistically different.[9]
Pycha's prospective, nonrandomized comparison of 130 high-risk patients included 55 ileal conduits, 34 colon conduits and 41 ureterocutaneostomies (median follow-up 16 months). Major diversion-related complications occurred in 18.1% of ileal conduits and 5.8% of colon conduits, and late surgical reintervention in 20% and 5.8%, whereas diversion-unrelated perioperative complications were 18.1% and 26.4%.[10] Baseline comorbidity was higher in the colon group (35.2% versus 12.7%).[10]
Metabolic and late complications
Urine exposure to ileum or colon can produce hyperchloremic metabolic acidosis and contribute to stone risk, bone demineralization and hyperammonemic encephalopathy in susceptible patients.[11] Vitamin B12 deficiency and fat malabsorption are more directly linked to ileal resection or pre-existing malabsorption than to urine exposure of an isolated colonic segment.[20] Severity depends on renal reserve, bowel surface and contact time, and drainage. Reabsorbed ammonium and sulfate inhibit renal calcium and magnesium reabsorption, as shown in patients with intestinal diversions and in a rat model.[17] Alkali and electrolyte treatment follows measured abnormalities and the pharmacology guidance.[2]
Alemozaffar's 41-patient distal-colon series reported, at ≥90 days, hypokalemia in 39%, hyperchloremia in 24.4% and metabolic acidosis in 34.1%. It also recorded ureterocolonic strictures in 4/41. Early ileus, bowel obstruction and an enterocutaneous fistula still occurred despite avoiding small-bowel anastomosis.[4]
Shimko's long-term report combined ileal and colon conduits: 643 of 1,057 patients (60.8%) had 1,453 diversion-related complications, a mean of 2.3 among the 643 affected patients. The 15.5-year median follow-up applied to the 213 survivors, not the entire cohort. Complications by domain were:[12]
| Domain | Patients affected |
|---|---|
| Bowel | 20.3% |
| Renal | 20.2% |
| Infectious | 16.5% |
| Stomal | 15.4% |
| Urolithiasis | 15.3% |
| Metabolic | 12.8% |
| Structural | 11.5% |
Monitor renal function, electrolytes/acid–base status, upper-tract drainage, infection symptoms and stoma function. A systematic review identified 47 published cases of de novo adenocarcinoma in colonic urinary diversions separated from the fecal stream; new local symptoms warrant evaluation of the conduit.[22] B12 risk also depends on prior ileal resection, nutrition and other causes. The EAU bladder cancer guideline states that B12 should be measured annually after cystectomy with bowel diversion (guideline text, not a graded recommendation).[13] New hydronephrosis warrants assessment for obstruction even when a nonrefluxing implantation was used.[7][13]
See Also
- Principles of Urinary Diversion
- Colon Shuffle
- Mainz Pouch III
- Ileal Conduit
- Vitamin B12 Supplementation
Videos
References
1. Hebert KJ, Swinney S, Johnson R, et al. "Outcomes After Colon Conduit Urinary Diversion: A Multi-Institutional Retrospective Study from the Reconstruction and Diversion: Improving Outcomes Group." J Urol. 2026;215(5):621–32. doi:10.1097/JU.0000000000004935
2. European Association of Urology. EAU Guidelines on Muscle-invasive and Metastatic Bladder Cancer. 2026. Urinary diversion and patient selection. Guideline.
3. Schmidt JD, Hawtrey CE, Buchsbaum HJ. "Transverse Colon Conduit: A Preferred Method of Urinary Diversion for Radiation-Treated Pelvic Malignancies." J Urol. 1975;113(3):308–13. doi:10.1016/s0022-5347(17)59469-0
4. Alemozaffar M, Nam CS, Said MA, et al. "Avoiding the Need for Bowel Anastomosis During Pelvic Exenteration — Urinary Sigmoid or Descending Colon Conduit — Short and Long-Term Complications." Urology. 2019;129:228–33. doi:10.1016/j.urology.2019.03.015
5. Theva DP, Kuhnen A, Babayan RK, Katz MH. Concurrent urinary and bowel diversion: Surgical modification with sigmoid colon that avoids a bowel anastomosis. Int Braz J Urol. 2020;46(1):108–115. doi:10.1590/S1677-5538.IBJU.2019.0194. Full text.
6. Davis BE, Noble MJ. "Simplified Urinary Diversion in Patients with Preexisting or Imminent Colostomy." J Urol. 1992;147(5):1245–7. doi:10.1016/s0022-5347(17)37529-8
7. Dagen JE, Sanford EJ, Rohner TJ. "Complications of the Non-Refluxing Colon Conduit." J Urol. 1980;123(4):585–7. doi:10.1016/s0022-5347(17)56031-0
8. Cody JD, Nabi G, Dublin N, et al. "Urinary Diversion and Bladder Reconstruction / Replacement Using Intestinal Segments for Intractable Incontinence or Following Cystectomy." Cochrane Database Syst Rev. 2012;(2):CD003306. doi:10.1002/14651858.CD003306.pub2
9. Hagemans JAW, Voogt ELK, Rothbarth J, et al. "Outcomes of Urinary Diversion After Surgery for Locally Advanced or Locally Recurrent Rectal Cancer with Complete Cystectomy; Ileal and Colon Conduit." Eur J Surg Oncol. 2020;46(6):1160–6. doi:10.1016/j.ejso.2020.02.021
10. Pycha A, Comploj E, Martini T, et al. "Comparison of Complications in Three Incontinent Urinary Diversions." Eur Urol. 2008;54(4):825–32. doi:10.1016/j.eururo.2008.04.068
11. Roth JD, Koch MO. "Metabolic and Nutritional Consequences of Urinary Diversion Using Intestinal Segments to Reconstruct the Urinary Tract." Urol Clin North Am. 2018;45(1):19–24. doi:10.1016/j.ucl.2017.09.007
12. Shimko MS, Tollefson MK, Umbreit EC, et al. "Long-Term Complications of Conduit Urinary Diversion." J Urol. 2011;185(2):562–7. doi:10.1016/j.juro.2010.09.096
13. European Association of Urology. EAU Guidelines on Muscle-invasive and Metastatic Bladder Cancer. 2026. Functional follow-up. Guideline.
14. Hendren WH. "Nonrefluxing Colon Conduit for Temporary or Permanent Urinary Diversion in Children." J Pediatr Surg. 1975;10(3):381–398. doi:10.1016/0022-3468(75)90102-5
15. Beckley S, Wajsman Z, Pontes JE, Murphy G. "Transverse Colon Conduit: A Method of Urinary Diversion After Pelvic Irradiation." J Urol. 1982;128(3):464–468. doi:10.1016/s0022-5347(17)52999-7
16. Morales P, Golimbu M. "Colonic Urinary Diversion: 10 Years of Experience." J Urol. 1975;113(3):302–307. doi:10.1016/s0022-5347(17)59468-9
17. McDougal WS, Koch MO. "Effect of Sulfate on Calcium and Magnesium Homeostasis Following Urinary Diversion." Kidney Int. 1989;35(1):105–115. doi:10.1038/ki.1989.15
18. Nieh PT, Althausen AF, Dretler SP. "Staged Ureterocolocolostomy Urinary Diversion." J Urol. 1978;120(4):402–406. doi:10.1016/s0022-5347(17)57199-2
19. Patel AR, Fergany A. Supravesical Urinary Diversion: Conduits. In: Montague DK, Gill IS, Angermeier KW, Ross JH, eds. Textbook of Reconstructive Urologic Surgery. Informa Healthcare; 2008:358–368.
20. Stein R, Rubenwolf P. "Metabolic consequences after urinary diversion." Front Pediatr. 2014;2:15. doi:10.3389/fped.2014.00015
21. WOCN Society. "WOCN Society, AUA, and ASCRS Position Statement on Preoperative Stoma Site Marking for Patients Undergoing Ostomy Surgery." J Wound Ostomy Continence Nurs. 2021;48(6):533–536. doi:10.1097/WON.0000000000000820
22. Sterpetti AV, Costi U, Grande R, D'Ermo G, Sapienza P. "De Novo Secondary Adenocarcinoma in the Colon Used as Urinary Diversion Not in Contact with the Fecal Stream: Systematic Review and Meta-analysis." Ann Surg Oncol. 2020;27(8):2750–2759. doi:10.1245/s10434-020-08300-4