Urinary Diversion & Bladder Substitution
When the bladder must be removed (most often for muscle-invasive cancer) or bypassed, urine needs a new route out — and the way you build it shapes the patient's life and their metabolism.
The big picture
When the bladder must be removed (most often for muscle-invasive cancer) or bypassed, urine needs a new route out — and the way you build it shapes the patient's life and their metabolism. The central trade-off is simplicity and reliability versus body image and continence: a stoma-and-bag conduit is robust and proven, while continent reservoirs and neobladders restore a more normal pattern at the cost of complexity. And whatever bowel you borrow to build the diversion brings its own metabolic consequences, because intestine reabsorbs urine.
The framework: know the three categories of diversion (conduit, continent reservoir, orthotopic neobladder), and the metabolic and nutritional consequences of using bowel.
Mechanism pathway
Tap any step to see why it happens.
Diagnostic algorithm
Each step answers one question. Tap to expand.
Board traps
Ileal conduit = simplest and most reliable; neobladder restores per-urethral voiding but needs a preservable urethra.
Bowel reabsorbs urine → metabolic disturbance — classically hyperchloraemic metabolic acidosis with ileum/colon.
Jejunum is the worst segment metabolically — used only as a last resort.
Long ileal segments → vitamin B12 deficiency — monitor and replace.
Preoperative stoma siting strongly affects patient satisfaction.