Intrinsic sphincter deficiency results in leakage with what level of stress?

• A. Leakage only during heavy lifting.
• B. Leakage with strong urge and detrusor contractions.
• C. Inadequate urethral closure due to weak or absent sphincter function, leading to leakage with minimal stress.
• D. Leakage due to bladder detrusor overactivity.

Answer: (C)

Intrinsic sphincter deficiency means the urethral sphincter can’t close the urethra adequately. Continence depends on the urethral closure pressure being higher than the pressure from inside the abdomen. When the sphincter is weak or absent, that closing force is too low, so even small increases in intra-abdominal pressure can push urine past the sphincter. That’s why leakage with minimal stress is the hallmark of this condition.

The other scenarios point to different problems: leakage only with heavy lifting suggests stress leakage with a functional sphincter still able to seal during minor stresses; leakage with strong urge and detrusor contractions or leakage due to detrusor overactivity indicates urge incontinence from bladder muscle overactivity rather than a weak urethral seal.