Call 911 if anyone's life is in immediate danger, or go to your local ER.
Here are some long term resources for those with post-traumatic stress disorder.
An eating disorder is a mental illness with physical consequences. The drive to be thin is a common symptom for many who struggle with an eating disorder, but not a root cause. Please don't emphasize weight/weight loss or physical appearance when addressing a possible eating disorder with a loved one. Rather than "you look great! I can tell you're finally eating!!!" Try saying "it's so nice to see you. How've you been?" Rather than "You've definitely lost weight. That's awesome. I'm so jealous, what's your secret?!" Say "It's so nice to see you. We need to hang out more. How've you been?"
Below are some additional resources.