Poop color chart: what's normal, what's food, and what needs a doctor

You glance down and… that’s not the usual color. Before you spiral, ask one question: what did I eat yesterday? A surprising number of “alarming” colors turn out to be beetroot, spinach or an iron tablet. But a few colors genuinely need attention, and this chart helps you tell the difference.

Why is poop brown in the first place?

Bile. Your liver makes it to help digest fat, and MedlinePlus explains bile salts give stool its normal brown color. Mayo Clinic adds that bile starts out yellow-green and changes color as it travels through your gut. So the speed of your digestion, and what you eat, both shift the shade.

What does each poop color usually mean?

Color	Usually	Sometimes	Action
Brown	Typical	n/a	Nothing to do
Green	Leafy greens, green food coloring, iron supplements	Fast transit, e.g. diarrhea	Usually fine; see a doctor if it lasts with diarrhea
Yellow	Diet; faster transit	Greasy, foul-smelling yellow can mean fat malabsorption	See a GP if greasy or ongoing
Black	Iron tablets, bismuth medicines, black licorice, blueberries	Bleeding high in the gut	Get urgent advice the same day unless clearly explained
Red	Beetroot, tomatoes, red food coloring, cranberries	Bleeding lower in the gut	Get it checked; urgent if bloody diarrhea or a lot of blood
Pale or clay	Some medicines	Lack of bile; liver, gallbladder or pancreas issue	See a doctor if it lasts several days, sooner with yellow skin or dark pee

Sources: Mayo Clinic, MedlinePlus, NHS.

How do I tell food from something serious?

1. Think back 24 to 48 hours. Beetroot? Spinach smoothie? Blue frosting? Iron tablets? Pepto-Bismol?
2. Check the shape. Note the Bristol type. Color plus diarrhea tells a different story to color alone.
3. Wait one or two poops if there’s an obvious food cause and you feel well.
4. Don’t wait for black, tarry poop you can’t explain, red blood, or pale poop with yellow skin or dark pee.

Common food color mix-ups

What you see	Food or medicine that can do it	Source	Still see a doctor if
Red or reddish	Beetroot, tomatoes, red food coloring	NHS bleeding page, MedlinePlus	It is not explained by food, or you see blood on paper or in the bowl
Black	Iron tablets, bismuth medicines, black licorice, blueberries	MedlinePlus	It is black and tarry, or you did not take any of these
Green	Green veg, green coloring	Pack 1 green page sources	It comes with diarrhea that does not settle

The MedlinePlus black stools page says beets and foods with red coloring can sometimes make stool look reddish, and that a provider can test stool for blood. If you are unsure, that test exists for a reason. See beetroot poop and blood on toilet paper.

Important: PoopAI does not analyze poop color, and it does not read color from photos. It logs Bristol type and an optional photo. Color notes are something you write down yourself.

What should I write down?

Doctors find specifics helpful. Note the date, the color, the Bristol type, anything you ate or took that might explain it, and other symptoms like dizziness, pain or weight loss.

Tue 19:00  Dinner: roasted beetroot salad
Wed 08:15  Poop: type 4, reddish  (note: beetroot last night)
Thu 08:20  Poop: type 4, brown

PoopAI logs Bristol type, meals and trigger tags. It does not analyze poop color, so add color as your own note when it matters.

Wrap-up

Most color surprises are your dinner saying hello. Black, red and pale are the exceptions: get those checked, and try not to feel embarrassed. As the NHS puts it, doctors are used to talking about this.

More on this

• Beetroot Poop: Red Poop After Beets, or Blood?