This is probably useless for your purposes, but I know from my dad that a pH score below 4 is particularly damaging for GERD patients when measuring acid in the esophagus. But your score could easily be scaled specifically for the probe test, or they could have different numbers for things in pediatric gastroenterology? Shame it's not you; I could have brought a lot more to the table.
Glad to hear he's doing well!
JD
