Fractional urination

Specialty: Nephrology and urology.

• two-stage urination
• double urination
• micturition fractionation

Why it occurs

• Large bladder diverticulum (saccular dilation of the bladder wall that accumulates urine during urination and which subsequently, after relaxing the detrusor, pours back into the bladder cavity, forcing a second urination)
• Severe benign prostatic hyperplasia (with marked infravesical obstruction that causes early fatigue of the detrusor muscle before evacuating all the urine, requiring a rest period of a few minutes to restart and complete emptying)
• Grade III-IV cystocele (bladder prolapse forms a urethral kinking; when the upper portion is emptied, the patient must reposition herself or apply manual vaginal pressure to empty the prolapsed lower portion)
• Neurogenic bladder with detrusor-sphincter dyssynergia (simultaneous and intermittent contraction of the sphincter mechanically interrupts urination repeatedly)

Initial workup

Urinary flowmetry with graphic recording (allows observing an intermittent or multiphasic voiding flow pattern); pre- and post-void vesicoprostatic ultrasound with dynamic evaluation of the bladder cavity (search for bladder diverticula); microradiographic voiding cystourethrography (CUMS); Complete urodynamic study.

Standard management

• Tamsulosin — 0.4 mg daily orally to relax the smooth fibers of the prostate and bladder neck, facilitating continuous emptying
• Bethanechol — 10-25 mg every 8 hours orally to improve the strength and duration of detrusor contraction in selected cases of muscle hypotonia, previously ensuring that there is no fixed obstruction of the urinary tract
• Surgical correction (such as resection of bladder diverticula, correction of cystocele or transurethral resection of the prostate if appropriate).