Does my friend have an eating disorder?

I am very worried for my friend :( he is 5'7" and weighs 120lbs and 18 years old you can see all his ribs and his collar bone and hip bones and back bones etc :( I thought something was going on but didn't want to say anything, he was hospitalised twice this year but wouldnt say why, he was bullied throughout his life at school because he was the "fat kid", I only know that he was in hospital for dehydration but haven't been told what else. He doesn't eat during the day and has 1/2 a piece of toast on the night :/ he also has pale skin and dry skin and can this be a symptom of anorexia? Thanks and thanks for your answers :)