Does anybody else get bathroom issues from Starbucks?

Me and my partner both have lactose intolerance and so we get milk alterniatives and vegan cream whenever we get Starbucks

Normally a cookies and cream frappuchino and a coffee frappuchino both with milk alternatives

But for some reason whenever we get Starbucks we also get a lactose intolerance related backlash from it too

Anyone else get that? It can't be just us two