You misunderstood, the beer is for your kidneys. Alcohol inhibits the adiuretic hormone, so you have to piss more often, especially if you drink beer which is around 95% water. Drinking a lot reduces the formation of kidney stones since they get flushed out before growing too big.

I wouldn't take painkillers tho, maybe Ibuprofen if it's unbearable, but stay away from Aspirin in conjunction with alcohol.