You stimulate an unlucky target's bowels into moving, the end result not being something not appropriate for the table. The target must make a Constitution saving throw or have their Charisma score be reduced by 14, due to the gooey mess running down from their clothes. If this reduces the target's Charisma to 5 or under, they can not cast spells based on Cha. the ability damage lasts until they get themselves cleaned up. On a successful save, the Charisma damage is only 4.