Is there a way to run EntityFieldQuery on all fields of a node that reference a user?
Thanks!
Can you try rephrasing your question? It is not clear what you are trying to accomplish. Do you want to load all nodes that use the same field to reference a user?
If so, you would use the fieldCondition() method. Something like
->fieldCondition('field_name', 'target_id', $uid)
See https://api.drupal.org/api/drupal/includes!entity.inc/function/EntityFieldQuery%3A%3AfieldCondition/7 for more information.