<human>: Can you succinctly summarize the text in 1-3 sentences?

The past few months I've been having issues with small amounts of alcohol (any type) causing nausea and vomiting. The other night I had only two beers and threw up a watery bile this morning (I even woke up feeling nausea). Another example was a pretty mild rum and coke that, after a few sips, made me feel pretty nauseous.

Before I had this issue I could drink a pretty good amount and be fine. Strangely I didn't have any trouble at my birthday where I had a few strong drinks. I'm not a big fan of drinking but I wonder what would cause this? I've read about Alcohol intolerance but I don't really have the symptoms.
<bot>: A couple of drinks can make me sick with even just a small buzz but I don't have the other symptoms of Alcohol intolerance. What kind of things could cause this?