Should a person afflicted with urinary incontinence who has an external stoma wait for the urine to dry before performing ablution (wudu') and prayer (salat), or should he perform ablution at the beginning of the prayer time given his excuse? And should he perform ablution immediately to catch the congregational prayer, or should he wait for it to dry and pray at home?

Firstly: Wudu' (ablution) for every prayer is valid for what emerges from the side opening, and this falls under the ruling of سلس ( سلس, meaning urinary incontinence or constant discharge).

Secondly: If the urine stops for a sufficient time to perform purification and prayer, then it is obligatory to wait for it to stop, and this is not considered سلس. Wudu' for the side opening does not mean that Wudu' is not invalidated by the exit of urine if it stops.