How's this any worse than ice cream and rootbeer or coke float? If anything, ice cream should give you the runs worse from the sugar on top of sugar on top flavoring. I would think it's just lactose intolerance that would make wet boom-booms.
I for one love soda and milk. Next thing up that people will find gross = egg soda from any Vietnamese place. It's exactly how it sounds and tastes delicious.