D.L.
G.,
I know my response is late, but wanted to mention possible allergies. My 2 children experienced similar situations and I was told at first it was a virus. I found out my daughter to alergic to milk, soy, nuts, eggs and wheat and my son has some similar allergies. May be the case. I had to elimate everything except rice for aoubt 2 days and then slowly start adding items back into their diets.
Hope this is not the case, but not too terrible difficult if it is, just requires some additional reading of ingredients.
All the best,
D