Is it permissible to hold back gas during or before prayer in order to preserve one's ablution?

If dinner is ready and a person desires it, they are excused from congregational prayer to eat until they are full. However, it is not permissible to make this a habit. This ruling extends to anything that distracts a person from having a present heart in prayer, such as repelling the two impurities (urine, feces, and gas). These should be relieved before prayer, even if it means missing the congregation, because the essence of prayer is a present heart.