(stomach problems) what would cause?

Someone to get sick from drinking before inebriation even happens, No idea why but lately when i drink alcohol, i tend to get sick before i even seem to get dunk, and not random sick, but drinking too much spins and vomiting sick. Not looking for a "well then dont drink" dumbass answer or some religious or moral crusader spewing the virtues of not drinking. Does anyone know some conditions that would cause this to happen (also, i seem to digest EXTREMELY slowly, showed by an endoscopy that showed food from 20+ hours before the test). Thanks in advance