Finally had the result for DS coeliac screen - its negative. Admittedly the Dr said he got that result over the phone and is waiting to see paperwork before 100% sure that is the case.
He has said to start DS on a gluten free diet asap and will review him in a year, we are getting an appt for the dietician.
Argh was so hoping it would be coeliac disease as it would be nice to know what we are dealing with but I feel just as lost as ever!