Overflow incontinence is associated with which bladder state?

• A. Underactive detrusor with small residuals.
• B. Overactive detrusor with large residuals.
• C. Underactive detrusor with high residuals leading to continuous or intermittent leakage.
• D. Efficient voiding with no residuals.

Answer: (C)

Overflow incontinence happens when the bladder can't empty properly, so urine remains after voiding and the bladder becomes overfull. This is most consistent with a weak detrusor that doesn’t contract well to empty the bladder, leaving a high post-void residual. As the bladder fills to high volumes, pressure rises and urine leaks out, either continuously or in small spurts between attempted voids.

That’s why the best description is an underactive detrusor with high residuals leading to continuous or intermittent leakage. If the residuals are small, or if the detrusor is overactive, leakage would more likely be urge incontinence rather than overflow. Efficient voiding with no residuals would not produce overflow leakage.