Well walk you through all the other possible causes, from common foods to underlying conditions, such as anal fissures. green stool may be scary to see, but the causes vary greatly from dietary causes to even discharged bile. More often than not, green poop is benign, so there isnt much cause for concern. A common stool color change, green poop can mean that youve been eating green vegetables (which are rich in chlorophyll) or green, blue, or purple food coloring, or it can be caused by any condition that leads to diarrhea or loose stools. Although stool is normally brown, the occasional green stool can fall within the normal range of stool colors. infants might have green stool as a result of not finishing breast-feeding entirely on one side, thus missing some of the high-fat-content breast milk, which affects the digestion of the milk protein hydrolysate formula, which is used for babies with milk or soy allergy. Green poop can be caused by a number of things, including diet and new medication. Here, doctors weigh in on seven things that can cause green poopand what you can do about it. green poop can be commonly caused by eating certain green foods, an infection that causes diarrhea, bile, or a side effect of medication. In addition, irritable bowel syndrome can cause green poop and stomach pain. Read below for more information on related symptoms, other causes, and treatment options. green poop is typically caused by eating too many chlorophyll-based foods or taking certain antibiotics. green stool when your feces look green is usually the result of something you ate, such as spinach. Certain medications or iron supplements also can cause green stool. Newborns pass a dark green stool called meconium, and breast-fed infants often produce yellow-green stools. Generally green stools in adults are caused by your food digesting too fast. As it digests it usually goes from green to brown before your bowel movement.