Overrunm, in my understanding and in basic language, breatholding tends to be in two types.
The temper type, usually triggered by anger/frustration, whereby the child remains, on the whole, bluish about the face because un-oxygenated blood is still circulating during the episode. These are not necessarily an indication of bad behaviour, as many are led to believe, as they can be triggered involuntarily, albeit some children can bring them about themselves.
The second, and which RAS is sometimes described as, is white/pallid breatholding, which results from a sudden or unexpected or extreme fright/hurt/pain and the child, whilst having bluish lips, is of a far more paler colour as the heart has usually slowed down almost to the point of stopping, so the un-oxygenated, bluish blood is not being pumped around. This type is always involuntary.
If it is the RAS type, it is best for you to be aware of this, so perhaps you could ask your GP to be more specific, especially as your son is having an operation soon. STARS can supply you with a leaflet 'Information for Anaesthetists and Dentists' as they need to be aware of the condition and take appropriate steps to try to avoid triggering an episode. Leaflets can also be obtained for helping explain the condition to others such as toddler groups, pre-school, school etc.
Whichever type it turns out to be, the most important thing is not to worry and to remain as calm as you can during an episode.
If you need it, STARS can give you lots of support.
Hope this is helpful.
butterfly