Medication side effect? Or something entirely different?

PLEASE...serious answers only.

I just started Lexapro and about 5 hours after my second dose I had green diarrhea. I have since had 4 other trips to the washroom with the same results and it's only been about 12 hours since this started. I also take Naproxen 1000mg and Nexium 40mg daily. I have been on those meds for months with no problems. Could it be the one beer I had with dinner last night? My doctor said I could still have an occassional alcoholic beverage. Normally I have a couple glasses of wine on the weekend. This was the first beer I've had since being on Lexapro though. Maybe my dinner just moved too quickly through my system because of the beer?