Does anyone else have little ones with a dairy intolerance? My son has a milk allergy so he does…

Does anyone else have little ones with a dairy intolerance? My son has a milk allergy so he does almond milk but now I think he just can't tolerate very much dairy. Occasionally he starts burping and it smells like vomit and then he will go between diarrhea and constipation and have a tummy ache. So, the only thing I can pinpoint is dairy in general because he's had eggs yesterday and today which he doesn't eat very often. Thoughts?