As an update, I've written to the doctor and now a complaint to the Primary Care Trust wanting an explanation to why I've been denied access to my 9 year old son's medical records. As a reminder, my son comes and stays with me for 54 nights a year, I do have PR and my name is on his birth certificate. The letter to the Primary Care Trust has taken the following into consideration.
In the GMC Guidelines for 0 - 18, the practitioner has to get the views of the parents to ascertain what's in the best interest of the child. The practitioner did not do that. I've also slightly modified a statement from
http://www.parentalalienation.org.uk/ where it defines Parental Alienation as "The systematic denigration of the non-resident parent by the resident parent with the intent of alienating children against the non-resident parent" which I believe my ex has done by coercing him prior to his 'prolonged conversation' with the doctor where the doctor deemed him Gillick competent. Further, due to my ex's acrimonious behaviour towards me I've sought to attend mediation, however, she has refused to attend. Food for thought for the doctor I think!
So I'll see what comes of that.