The Grand Ayatollah Khamenei answered a question about performing Wudhu and Salaat/Salaah for incontinent persons.
Question: What is the duty for Taharah (cleanliness), Wudhu and Salaat for the person who is ill and incontinent?
The Grand Ayatollah Khamenei: If the person knows that from the start of the time for Salaat to the end of it can manage the time to perform Wudhu and perform Salaat with Wudhu, must perform Salaat in that time. Otherwise, if during Salaat urine comes out a few times, with each Wudhu can perform a Salaat; meaning for each Salaat one Wudhu is enough, even if the Wudhu is invalidated during that Salaat.
But if urine comes out continuously from the person in a way that for each time wants to do Wudhu it gets very difficult, can perform multiple Salaats with one Wudhu, on the condition that between two Salaats, no urine comes out. Such a person must avoid impurity (Najasah) reaching his clothes and body, and the Wajib precaution is that if there is no great difficulty, the place that urine comes out is cleansed (Tat’heer) before any Salaat.
Source: Shafaqna English