A massive myth about eating disorders is that purging is making yourself sick. While that’s true, there are lots of other things that people do to “get rid of” food. Exercise, fasting and laxatives are used for the same purpose as being sick.
It’s also commonly thought that vomiting is more dangerous. Didn’t it ever occur to anybody that exercise can damage your bones, muscles and joints? Or strain your heart? Or that laxative abuse can damage you so much that you don’t make it to the bathroom in time? No, they probably didn’t.
Every eating disorder is different.