All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It is disliked for one to pray while withholding urine, faeces or wind, for it is proven that the Prophet, sallallaahu ‘alayhi wa sallam, forbade performing prayer in such a state. That is because performing prayer in such a state diverts the praying person, and makes him lose Khushoo (submission). However, whoever prays in such a state, his prayer is valid though disliked.
There is no doubt that to offer the prayer with a new ablution without withholding those things is more appropriate than to offer it with a previous ablution while withholding them for the reasons we have already mentioned. Furthermore, to renew ablution for every obligatory prayer is a recommended Sunnah, even if it was not invalidated.
Allaah Knows best.