Bladder and bowel dysfunction commonly occurs in individuals undergoing rehabilitation. In keeping with the objectives of this book, the goal of this chapter is to provide general principles of assessment for a learner, rather than an in-depth review of the subject. The chapter is divided into two sections, the first on neurogenic bladder and the second on neurogenic bowel, with the focus on assessment of the bladder and bowel.
Anatomy and Physiology of the Upper and Lower Urinary Tracts
Although evaluation and management usually focuses on a person's “neurogenic bladder,” it is important to remember that changes in the lower tracts, such as poor drainage or high bladder pressures, often have a direct impact on the kidneys. Therefore, an understanding of the entire urinary tract function, neurophysiology, and urine transport is essential when planning optimal assessment and treatment. The urinary tract is divided into the upper and lower urinary tracts. The upper tracts are composed of the kidneys and ureters. The lower urinary tracts are composed of the bladder and urethra.1,2
The kidney consists of two parts: the renal parenchyma and collecting system. The renal parenchyma secretes, concentrates, and excretes urine into the collecting system. Once urine drains through the multiple renal calyces, it collects in the renal pelvis. Active forces of urine transport then occur due to peristalsis of the calyces, renal pelvis, and ureter. Once the urine bolus arrives at the bladder, it travels through an important structure, the ureterovesical junction (UVJ).3 The UVJ is where the ureters traverse obliquely sandwiched between the muscular and submucosal layers of the bladder wall for a distance of 1 to 2 cm before opening into the bladder. This submucosal tunnel is designed as a one-way valve to allow urine flow into the bladder, but prevents reflux backward up into the ureter2 (Fig. 5–1). A common misconception is that high pressures in the bladder will cause vesicoureteral reflux, but the reverse is true. Sustained high intravesical pressures will inhibit drainage from the kidney and can over time cause upper tract damage.
The ureterovesical junction : Normal ureterotrigonal complex. (A) Side view of ureterovesical junction. Waldeyer's muscular sheath invests the juxtavesical ureter and continues downward as the deep trigone, which extends to the bladder neck. The ureteral musculature becomes the superficial trigone, which extends to the verumontanum in the male and stops just short of the external meatus in the female. (B) Waldeyer's sheath is connected by a few fibers to the detrusor muscle in the ureteral hiatus. This muscular sheath, inferior to the ureteral orifices, becomes the deep trigone. The musculature of the ureters continues downward as the superficial trigone. (Reprinted with permission from Tanagho EA, Pugh RCB. The anatomy and function ...