Some organizations can be found on this website and are listed on other websites on the topic of eating disorders. The treatment options are different and will depend on what is offered in your area. The condition of the person suffering will also determine the kind of treatment they will require. Some patients are hospitalized quickly if necessary. Some hospitals provide out-patient programs and important thing to know is, where to find it and what's available to you.
Treatment usually depends on some kind of health monitoring with combined therapy.
What works for one person may not work for another and you may have to search around to get the best care that suits you or your loved one. Nutritional counseling is sometimes recommended to help some patients with their eating habits and patterns. My insurance coverage did not cover it but if you have insurance that does, it can be a help for some people. I've heard people who tell me they love their therapist and others who don't like their therapist. It's obvious that those who like their therapist stay in treatment while those who don't end up leaving.