What is the ruling on doubting an increase or decrease in the obligatory and supererogatory acts of ablution (wudu), whether the doubt occurs during ablution or after finishing it?

Whoever doubts having omitted an obligatory act (fard) of ablution (wudu) or prayer (salat) before completing what they are engaged in, must perform that which they doubted, because whoever doubts a pillar (rukn) builds upon certainty. This applies if the person is not prone to frequent doubts. However, if the doubt occurs after completing the act of worship, it is not to be heeded. And whoever doubts a sunnah and has not passed its place should perform it; if they have passed its place, they should perform it as long as another sunnah has not taken its place.