Does a small amount of urine (water) exiting the male organ after relieving oneself and leaving the restroom invalidate ablution and prayer?

Istibra (seeking clearance from impurity) is obligatory after relieving oneself, to ensure freedom from minor ritual impurity (hadath). This is a matter of consensus. Whoever is certain of having performed istibra should not pay attention to subsequent doubts, because certainty is not removed by doubt. If one is certain that impurity has exited, then it must be removed. Frequent doubts should be ignored to avoid falling into whispers (waswas). Likewise, doubts after completing an act of worship should be disregarded. The questioner must ensure they have performed istibra and achieved ritual purity, and then no attention should be paid to subsequent doubts.