My friend is a nineteen year old male, and he shows definite signs of bulimia. He has lost 10 pounds in the past two weeks, throws up once a day (and has been for three weeks now), works out excessively, avoids eating, and has binge eating episodes. He has very low self esteem (of his body physique). I've told him to stop or get help, and have shown him websites about the effects it could have on his body if he continues, but he refuses to tell anyone besides me or get treatment. What else can I do?