I'm looking for a translation of a Dutch/Flemish word. We call it "VZW (vereniging zonder winstoogmerk)" This is a organisation like a non-profit organisation. But is't smaller, raised by just few people.
In our case, we have a VZW Medical Failures. People can join the "VZW" and they write letters to the organisation where they describe the facts/failures that happend in the hospital. The goal is to recieve medical and juridical opinions from the "VZW".

Is there some kind of translation for this organisation?

Sounds like an OMBUDSMAN. This is an indepent person or small organisation that accepts complaints (usually from the public) and makes a ruling that may include compensation to the victim.
Googlr translate gave me; non-profit organization.