I have had green stool the last two days should I go to the ER?

Did you eat anything with food coloring in it like cereal maybe?

Not normally cause for concern. It means your food has passed through your bowels fast with the aid of a laxative. If no, then see your doctor If you are alarmed.

I believe that green in the stool is extra bile, and it is not cause for concern.

It is something I would go to the doctor for, not urgently but quickly. That being said there are certain purple food dyes that will cause this to happen. For example I had a FULL pound package of blueberry twizler candy. The next day I left several kerry green turds in the toilet. Not something I was concerned with but if it happened for longer then it takes to void that from my system I would have gone to a doctor.

I ate Fruit Loops cereal and had green poop...doesn't last for long but it is there once or twice...lol.

You really don't provide a lot of information. Even if you had, there are no doctors on this site. If you're concerned then I'd see your doctor. I don't think there's a reason to go to the ER, but again that's your decision, we can't give you a medical opinion.