Epiploic appendagitis appears to be solely caused by physical interference with epiploic appendages. This interference is in the form of torsion or tension. While the cause of this tension / torsion is unknown, the condition is self-limiting and thus not dangerous. The more the appendage is twisted or pulled, the more likely 'it wants to' come back.
It appears that the torsion is more likely with appendages that are abnormally longer or larger.