Stool color: When to worry - Mayo Clinic www.mayoclinic.org/stool-color/expert-answers/faq-20058080Private View Answer From Michael F. Picco, M.D. Stool comes in a range of colors. All shades of brown and even green are considered normal. Only rarely does stool color indicate a potentially serious intestinal condition. Stool color is generally influenced by what you eat as well as by the amount of bile — a yellow-green fluid that digests fats — in ...