GPs do not share patient records in their entirety. They only publish relevant information for continuity of patient care in summarized electronic health records (Sumehr).
Each hospital institution or doctor is in full control of what is published or not on the Brussels Health Network but is required to respect the patient’s privacy. If you do not want information to be shared, make a direct request to your healthcare provider to not share your information. In any case, you have the possibility to make a cross on a specific document later on.