What should you do if your ablution is nullified every time you prostrate, and should you shorten the prayer or complete it?

If prolonging prostration leads to the emission of gas and nullifies ablution, then it is prescribed to shorten prostration to preserve purity and the integrality of prostration. If the emission of gas occurs merely by prostrating, then do not prostrate; rather, nod your head while sitting, because preserving purity—which is a condition for the validity of prayer—takes precedence over fulfilling one of its pillars.