What could be a cause of neon green stool. i haven't ate anything remotely green. should i be concerned?

Bile: It means something is irritating the liver or gallbladder or both.

No: The color of stool is determined by the food we consume and the presence or lack of bile content in the stool. While stool may have multiple colors (ie. clay/white, green, brown) if it returns to your baseline color, there is little to worry about. Sometimes chemicals in our diet can affect the change you are experiencing. If it continues, see your doctor for more advice.