Overflow incontinence occurs when the bladder becomes overdistended due to incomplete emptying, leading to increased pressure and involuntary leakage of urine. This condition is often caused by bladder outlet obstruction or impaired detrusor muscle contractility. Unlike stress or urge incontinence, overflow incontinence involves continuous or intermittent leakage as the bladder exceeds its capacity. Recognizing this helps guide appropriate surgical interventions such as relieving obstruction or addressing neurogenic bladder dysfunction.

Reference: Campbell-Walsh Urology, Wein et al., 12th Edition.