The color of your stools is often a reflection of what you eat. Black stools, for example, can result from eating blueberries or taking medications that contain bismuth subsalicylate, such as Pepto-Bismol.

Your poop may be green if you eat a lot of green vegetables, such as spinach and broccoli, because these foods contain large amounts of the green pigment chlorophyll.

Other dietary causes for green stool are iron supplements and green food coloring, which can be found in flavored drink mixes, ice pops and birthday-cake icing.