Last night i went to the bathroom and had gery stool should i be concerned?

Depends on details: Having several grey stools can mean a liver or gallbladder problem. If bile from the liver or gallbladder doesn't mix with the digesting foodstuffs inside the intestine, then the stool can have a grey color. One's primary care doctor can evaluate, and may order some lab tests. He may refer to a gastrointestinal specialist if needed.