What is the difference between gin that is just "gin" and the "distilled gin"? Is the distilled gin better?

I had a bottle of gin in the house and occasionally make martinis. I was out of the "distilled" gin and without realizing brought the same brand name, but it didn't say "distilled" on the bottle. The next day I did not feel so well after having the martini made with the gin that was not distilled.