a blocked fart

There's this spectacular perspective that starts as a feeling of am emerging fart, but in a more strenous manner than normally, and then when you start giving it a push, you will all of a sudden feel a small-size, immature brick pushing out instead. A short panic follows, relieved only seconds later by the fart swooshing out over the shoulder of the blocking poop that itself retreats to its "under construction" site.