I would recommend reading 'Playful parenting' by Lawrence j Cohen, he's a psychologist and seems to know his stuff. It may be a case of your lil boy having to play through his troubling experiences or rather express his experiences through play. This can sometimes seem quite unpleasant to adults. The book helped me realise that even the sometimes unpleasant or unusual behaviour was really quite normal and gave me ways to help both me and my dd feel better and enjoy life more.
another vote for playful parenting -really good book also I find one on one play dates - even when the children normally get on well can be quite full on and often involve some kind of argument -also remember that is normal for children to argue more than adults do so as some else said maybe go to the park, something like pond dipping was a big hit with my DS and his friends today that kind of thing
just to say there is a bullying section on mumsnet and they might have some ideas/give you some support and from my experience of mental health (you are in the UK right?) - keep pushing for the appoitments - get the GP to follow up and possibly someone else - its does make a difference for getting the help your son needs
Thank you ladies. I will have a good look at youngminds Alice. Our school is very small and very involved with our problem and haven't mentioned any groups they run that might help. Maybe we could start one up though. (Yikes!)
AnOtherName I should have thought of exploring the Mumsnet bullying section but hadn't. I shall have a browse.