(from the 3rd link listed below)An eating disorder is an eating disorder, and with it comes the same number of potential health problems for the individual as any other peson with an ED.
I think there's a lot of misconceptions out there not only about what an eating disorder is (ie. you'll always get the "it's just for attention" or "she's not skinny enough" etc.) but also about those people that are suffering, but don't technically "qualify" for a DSM diagnosis of anorexia or bulimia or even binge-eating disorder. There's so much overlap btwn all of them, but for ex. the fact that someone starves and purges but manages to maintain a close to normal weight doesn't mean they're not in need of help or that things are "okay". Or how many people know about bulimirexia? They're just as "valid" as any other ed or problem.
Anyways, I think these links are really good at explainig EDNOS (eating disorders not otherwise specified) just to get a general idea:
Eating disorders not otherwise specified