Ileal segment is the best for urinary diversion after cystectomy. Still better method is "Continent cutaneous diversion" method. But the best method is "Orthotopic neobladders". "Incontinent cutaneous urinary diversion" by ileal conduit: a segment of ileum is exteriorized in the form of a stoma through the abdominal wall, around which an appliance is secured and into which urine continuously drains. "Continent cutaneous diversions" — All continent cutaneous reservoirs rely upon a low-pressure pouch constructed of various detubularized bowel segments and a functional mechanism that connects the reservoir to the skin, designed to prevent involuntary urine flow. The most obvious advantages of this type of diversion are the ability to avoid continuous urine drainage and the need for an external appliance. These continent cutaneous diversions require intermittent clean self-catheterization through the stoma both to empty the reservoir and to irrigate mucous. No stomal appliance is usually required. Although continent cutaneous diversions have been largely supplanted by the orthotopic neobladder, this procedure is used when the urethra or bladder neck is non-functional or involved by tumor, and avoidance of an external appliance is desired. "Orthotropic neobladders"— Orthotropic neobladders are internal reservoirs that are connected to the native urethra and rely upon the external striated sphincter for continence. These reservoirs are constructed from a segment of detubularized intestine (usually ileum) anastomosed to the native urinary outflow tract. Because this approach facilitates the restoration of normal self-image by approximating normal voiding, construction of an orthotropic neobladder has become the procedure of choice for most patients following cystectomy for bladder cancer in both men and women. It is contraindicated if the urethra is nonfunctional or involved with tumor.