Intestinal Segments
Ileum, colon and ileocecal segments provide vascularized tissue for urinary reservoirs, conduits, channels and selected genital reconstruction. Their mesenteric blood supply is preserved; they are included in this library as tissue substitutes rather than free grafts.
See the overview article for the reference summary: Grafts in GU Reconstruction, and the anatomy article: Bowel Anatomy. Bowel anastomosis technique is covered in Bowel Anastomosis. For segment selection when a prior bowel anastomosis or resection already exists, see Reoperative Bowel Harvest.
Core Principle
Intestinal segments are not free grafts in the strict technical sense; they are vascularized visceral segments isolated on a mesenteric pedicle and repurposed as reservoir, conduit, channel, or lining. They are included in the grafts library because the reconstructive question is the same: which tissue best substitutes for the missing urinary or genital surface?
Bowel retains mucus secretion and absorptive functions after transfer. Detubularization disrupts coordinated contractions and improves reservoir geometry; it does not abolish all intestinal smooth-muscle activity. The choice must account for perfusion, urinary contact time, renal function, previous bowel surgery and lifelong follow-up.[1][2][6]
Ileum
Ileum is widely used for urinary diversion and augmentation. Its suitability depends on actual mesenteric reach and perfusion, the amount and location of bowel remaining, and the planned reservoir or conduit; previous surgery, radiation or bowel disease may change the choice.[1][6]
| Property | Reconstructive implication |
|---|---|
| Long mesentery and multiple arcades | Potential pelvic reach; confirm a well-perfused segment reaches without mesenteric tension |
| Thin wall and good compliance after detubularization | Useful for low-pressure reservoirs |
| Mucus production | Requires irrigation education in catheterized reservoirs |
| Terminal ileum absorbs B12 and bile salts | Preserve functioning distal ileum when possible; document the harvested segment and arrange B12 follow-up |
Applications
- Ileocystoplasty and broader augmentation cystoplasty
- Orthotopic neobladder families such as Hautmann neobladder and modified Studer pouch
- Ileal conduit
- Ileal ureter and Yang-Monti ileal ureter
- Yang-Monti catheterizable channel
Sigmoid Colon
Sigmoid colon offers a larger caliber and a pedicle supplied through the inferior mesenteric system. It can provide a urinary segment or a mucus-secreting vaginal substitute. Both ileal and colonic urinary segments can cause hyperchloremic metabolic acidosis; severity also depends on exposed surface area, contact time and renal reserve.[1][2][6]
| Property | Reconstructive implication |
|---|---|
| Larger caliber and thicker wall | Useful for reservoirs and neovagina, but can be bulky in a narrow pelvis |
| IMA / sigmoid-artery pedicle | Requires attention to marginal artery and rectosigmoid watershed perfusion |
| Persistent mucus production | Plan reservoir irrigation or neovaginal secretion care according to the reconstruction |
| Intestinal electrolyte exchange during urine contact | Monitor for hyperchloremic metabolic acidosis |
Applications
- Sigmoid cystoplasty
- Sigmoid neovagina / bowel vaginoplasty when skin-graft or peritoneal options are unsuitable
- Colon conduit or colon shuffle when ileum is unusable
Ileocecal Segment
The ileocecal segment combines terminal ileum, cecum, appendix, and right-colon territory. Its special value is that the ileocecal valve and appendix can be incorporated into continent cutaneous systems, while the right colon supplies reservoir capacity.[1][4]
| Component | Reconstructive role |
|---|---|
| Cecum / right colon | Reservoir wall for continent cutaneous diversion or augmentation |
| Terminal ileum | Catheterizable limb, efferent limb, or reconfigured channel |
| Ileocecal valve | Part of the continence mechanism at the catheterizable outlet in an Indiana-type reservoir; not itself a ureteric antireflux mechanism |
| Appendix | Natural small-caliber catheterizable channel when present and usable |
Applications
- Ileocecal cystoplasty
- Indiana pouch
- Appendicovesicostomy / Mitrofanoff: an appendix-based channel can be harvested without transferring the whole ileocecal segment
- Ileocecal continent cutaneous diversion families, including Mainz / right-colon variants
Metabolic Complications
Long-term follow-up should assess renal function, electrolyte and acid-base disturbances, emptying, stones and symptomatic infection. For patients with bowel urinary diversion after cystectomy, the EAU recommends annual B12 testing; augmentation and other reconstructions need follow-up matched to the segment and underlying condition.[5][6]
| Issue | Most relevant segments | Practical response |
|---|---|---|
| Hyperchloremic metabolic acidosis | Ileum and colon | Monitor bicarbonate / chloride; treat with oral alkali when clinically significant |
| Mucus production | Intestinal reservoirs and channels | Teach irrigation for catheterized reservoirs; evaluate stones and recurrent blockage |
| Vitamin B12 deficiency | Terminal ileum | Preserve terminal ileum when possible; monitor and supplement B12 |
| Bile-salt malabsorption | Terminal ileum | Watch for diarrhea and fat-soluble vitamin issues after longer resections |
| Stones and chronic bacteriuria | Reservoirs and catheterizable systems | Hydration, complete emptying and mucus management; treat symptomatic infection, not colonization alone |
| Late malignancy | Augmented bladders and bowel reservoirs | Investigate hematuria or other concerning new symptoms; use reconstruction-specific surveillance, not a blanket annual endoscopy rule |
Patients with reconstructed lower urinary tracts commonly have asymptomatic bacteriuria. Routine screening and treatment are not recommended solely because a bowel segment is present; pregnancy and urinary procedures breaching the mucosa require separate assessment.[7] Mucus has been implicated as a stone nidus, but the small Khoury study was not a trial proving a particular irrigation regimen.[3]
For the dedicated management pages, see Renal Function & Metabolic Surveillance, Mucus Management, Vitamin B12 Supplementation, and Urinary Acidifiers & Alkalinizers.
References
1. Santucci NR, Velez A. "Physiology of Lower Gastrointestinal Tract." Aliment Pharmacol Ther. 2024;60 Suppl 1:S1-S19. doi:10.1111/apt.17900
2. Kiela PR, Ghishan FK. "Physiology of Intestinal Absorption and Secretion." Best Pract Res Clin Gastroenterol. 2016;30(2):145-159. doi:10.1016/j.bpg.2016.02.007
3. Khoury AE, Salomon M, Doche R, et al. "Stone formation after augmentation cystoplasty: the role of intestinal mucus." J Urol. 1997;158(3 Pt 2):1133-1137. doi:10.1016/S0022-5347(01)64404-5
4. Rowland RG, Mitchell ME, Bihrle R, Kahnoski RJ, Piser JE. "Indiana continent urinary reservoir." J Urol. 1987;137(6):1136-1139. doi:10.1016/S0022-5347(17)44428-4
5. Stabler SP. "Vitamin B12 Deficiency." N Engl J Med. 2013;368(2):149-160. doi:10.1056/NEJMcp1113996
6. European Association of Urology. Muscle-invasive and Metastatic Bladder Cancer, 2026. Follow-up of functional outcomes and complications. Guideline.
7. European Association of Urology. Urological Infections, 2026. Asymptomatic bacteriuria in reconstructed lower urinary tracts and before urinary procedures. Guideline.