What is the ruling on the purity of one who experiences urinary leakage, and is ablution required for it?

One who does not suffer from urinary incontinence must not perform ablution (Wudu') until they are certain their urinary system is completely empty. Scholars recommend Istibra', which means ensuring the urine has been completely discharged and any dripping has ceased. If one finds difficulty in this, they are considered to be in the same ruling as someone afflicted with incontinence.