Must one repeat the prayer if a small amount of madhy is found after finishing it?

Madhi (pre-seminal fluid) is impure, and its emission nullifies wudu (ablution). If a worshiper finds it after prayer, there are two scenarios:

1. If its emission is likely to have occurred after the prayer: Their prayer is valid and does not need to be repeated. The default assumption is the validity of the purification and prayer. It is recommended to repeat it as a precautionary measure. 2. If they know it was emitted during or before the prayer without having purified themselves: Their prayer is invalid and must be repeated.