What condition most commonly leads to overflow incontinence?

• A. Prostate cancer
• B. Kidney stones
• C. Urethral stricture
• D. Urinary retention

Answer: (D)

Overflow incontinence happens when the bladder can’t empty fully, so it becomes overdistended and urine leaks as pressure builds. The most common trigger is urinary retention—outflow is blocked or the detrusor muscle isn’t able to push urine out effectively, so the bladder gradually fills and leaks small amounts around the outlet. In men, an enlarged prostate often narrows the urethra and prevents complete emptying, leading to this leakage pattern. Other conditions like kidney stones, urethral stricture, or prostate cancer can cause urinary problems, but they are not the typical cause of the chronic retention that leads to overflow. Therefore, urinary retention best explains why overflow incontinence occurs.