Purity: Incontinence with Respite for Wudu and Part of Prayer
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 307:
If a person finds respite [from the illness mentioned in the previous ruling] to perform wuḍūʾ and only part of the prayer, and during prayers some urine or faeces is discharged once or a few times, the obligatory precaution is that in the respite period he must perform wuḍūʾ and prayers. Furthermore, it is not necessary that he renew his wuḍūʾ on account of a discharge of urine or faeces during or after prayers; rather, one wuḍūʾ will suffice for several prayers unless he does something else that invalidates his wuḍūʾ, such as sleeping, or he discharges urine or faeces in a normal manner. However, it is better that he perform wuḍūʾ for the next prayer.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)