Bulimia nervosa, commonly known as bulimia, is an eating disorder. It is generally considered 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 use of laxatives, enemas, diuretics or other medication; and excessive physical exercise. The word bulimia comes from the the Latin (būlīmia) from the Greek βουλῑμια (boulīmia), ravenous hunger, compounded from βους (bous), ox + λῑμος (līmos), hunger.

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http://en.wikipedia.org/wiki/Bulimia_nervosa