Purity: Preventing Discharge and Treating Incontinence
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 312:
If someone cannot control the discharge of urine or faeces, he must prevent their discharge during prayers if it is possible for him to do so; and it is better that he prevents it even if he incurs an expense in doing so. If his illness can be treated easily, it is better that he is treated.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)