Bulimia nervosa, more commonly known as bulimia, is an eating disorder. It is a psychological condition in which the subject engages in recurrent binge eating followed by an intentional purging. This purging is done in order to compensate for the excessive intake of the food and to prevent weight gain. Purging typically takes the form of vomiting; inappropriate or excessive use of laxatives, enemas, diuretics or other medication; excessive physical exercise; or fasting.