Stool tends to be brown. A change in color to green poop can be due to a digestive disorder, stomach bug, or something you ate.
Green poop is also a common side effect of iron supplements and some medications. Green diarrhea (loose stools) can be a sign of a viral infection. An excess of bile, a digestive fluid produced by the liver, can also cause poop to turn green.
That said, you should see your doctor if the green poop (or another stool color change) is ongoing, or if you have other symptoms, like fever, diarrhea, nausea, vomiting, or pain.
This article discusses some possible causes of green poop (whether it is dark, bright, light green, or floating). It also covers reasons for green poop in pregnant women, infants, and children, and when to see a healthcare provider about green poop.
Foods That Cause Green Poop
Stool is digested food. Green poop is often the result of eating foods that are rich in green, blue, or purple pigments—either natural hues or food coloring. Here’s a list of foods that can cause green poop.
Your poop can be green after eating meals with green vegetables, such as:
- Swiss chard
- Bok choy
- Green beans
Green fruits like these can also cause green poop:
- Green apples
- Green olives
- Green grapes
Green poop after eating these foods doesn’t mean there’s something wrong. Dark green, leafy vegetables and green fruits are rich in chlorophyll—the pigment that gives plants their color. Any of these plant foods can cause green poop if you eat enough of them.
Nuts like pistachios, seeds like hemp seeds, and herbs like parsley, basil, and cilantro are also rich in chlorophyll. Matcha, a type of powdered green tea, can also make stools a bright green hue.
A small serving may not be enough to give you green poop. Green poop is more likely if you’re eating large servings, like those found in smoothies, juices, pureed soups, large salads, or guacamole.
Some foods contain green (or blue and yellow) food coloring that may turn your poop green. These dyes are sometimes used in canned green peas, green beer, breakfast cereal, candy, jarred pickles, salad dressing, drinks, icing, and sweets. You’ll also see these dyes in holiday food.
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Blue and Purple Foods
Deep blue or purple foods can sometimes lead to green poop. This includes blueberries, grapes, and red wine.
Purple (or red and blue) food coloring can also cause dark or bright green poop. These dyes are in the following:
- Drink mixes
- Grape Kool-Aid and soda
- Frozen ice pops
- Cake icing
- Blue juices
- Packaged fruit snacks
- Grape-flavored Pedialyte
Food dye colors are often used during Kwanzaa, Easter, Eid Al-Fitr, Saint Patrick’s Day, and Halloween.
Coffee, Spicy Foods, and Alcohol
As bile moves through the small intestine to the large intestine, it changes color from green to yellow to brown. This is due to how bacteria in the large intestine act on bile salts.
Coffee, alcohol, jalapeños, and chili pepper can make you have to poop more quickly. These foods cause a laxative effect that makes food rush through your intestines too fast for it to change from green to brown.
Special Diets Can Cause Green Poop
Some diets are also more likely to cause stool to turn green. Green poop can mean the food is not fully digested or you have an abundance of bile (digestive juices). The following diets may cause green poop and the meaning behind it.
Colon cleanse diet or colonoscopy prep may cause green stools by increased motility, causing food to rush through your intestines.
Fruit, Vegetable, or Juice Fast
Eating or juicing lots of green veggies and fruits can turn your poop green. Some juice cleanses will also up your chlorophyll intake and make green poop more likely.
A high-fat diet like the keto diet may give your poop a bright green hue. With a high-fat diet, your body makes more bile to digest these fats. So, your stool may come out with more green bile.
Medical Causes of Green Poop
Medical issues can sometimes cause green stool. Green poop is often associated with diarrhea, which causes stool to move faster through the digestive tract. It can also be due to digestive health problems
Health concerns that cause green poop from diarrhea include:
Floating green stools can be a sign that your intestines aren’t absorbing fat properly. The occasional floater is normal. However, if it is an ongoing occurrence, it could be a sign of a more serious health issue.
Green stools that have visible mucus could mean the lining of your intestines is inflamed. If you notice this often, it could be a sign of a condition that may require treatment, especially if involves other symptoms like diarrhea, constipation, pain in your abdomen, nausea, or vomiting.
A rare but serious cause of green poop in kids and adults is poisoning by chemicals such as paraquat, a pesticide in weed killers.
Liver or Gallbladder Problems
Bile is a a greenish-yellow liquid made in your liver and stored in your gallbladder. If you have green poop or green diarrhea, then there may be excess bile in your stool.
Some types of liver disease that cause increased bile production can result in yellowish or green, watery diarrhea. This effect is seen in non-alcoholic fatty liver disease.
Drugs and Supplements That Cause Green Poop
Taking iron supplements can change the color of your poop to dark green (or black). Other vitamins, supplements, and teas that can cause green poop include:
- Senna, cascara sagrada, rhubarb, and fiber supplements
- Supplements that contain chlorophyll, like wheatgrass, spirulina, barley grass, chlorella, and blue-green algae
- Yerba mate tea
- Medication that can cause diarrhea as a side effect, like metformin, Lexapro (escitalopram), Nyquil, Zoloft (sertraline), or antibiotics like ciprofloxacin
Causes of Green Poop in Pregnancy
Green poop is common during pregnancy and is usually nothing to be concerned about. It can mean different things at different points during pregnancy, such as:
- First trimester: Some pregnant people experience green bowel movements in the very early days of pregnancy—before they even know they are pregnant.
- Second trimester: Iron supplements or prenatal vitamins, which have more iron than the typical multivitamin, can cause green poop throughout pregnancy.
- Third trimester: Green stool may occur more frequently as your due date approaches. This is because food often moves through the intestines faster in late pregnancy.
- Postpartum: Green poop in the weeks after pregnancy is usually related to diarrhea. Reintroducing caffeine, artificial sweeteners, or dairy after pregnancy are common causes of postpartum diarrhea.
Causes of Green Poop in Babies, Toddlers, and Older Kids
A newborn’s first stool (meconium) is usually green or black in color. Meconium usually stops after they are three days old.
In older babies and children, green poop can be due to a sensitivity to a new food or viral or bacterial infection. If you have any questions or concerns about your baby’s poop, check with your pediatrician.
Baby Formula and Green Poop
Certain formulas can give baby’s poop a green hue. Dark green (or green-black) poop in babies is commonly caused iron supplements or iron-fortified formula.
A sensitivity to milk proteins, digestive-enzyme deficiency, or carbohydrate malabsorption can also cause green poop in formula-fed babies.
Green Poop in Breastfed Babies
If a breastfed baby has green poop, it could be something in the mother’s diet, like green veggies or food made with green or purple food coloring. In some cases, it could be that the mother or baby is sensitive or allergic to something in their diet.
Green poop in breastfed babies (particularly “EBF” or exclusively breastfed babies) can be a sign that the baby is getting too much low-calorie, low-fat foremilk (the milk that comes first in a feeding) and not enough hindmilk, which is higher in fat.
It could also mean that the baby isn’t feeding long enough on each breast. The baby may not be draining the breast enough. Or, there could be an oversupply of breast milk. A lactation consultant may be able to help find the issue.
Green Poop in Toddlers
In toddlers, green poop and foul smelling diarrhea are often associated with teething. But that’s just an old wives’ tale, according to the American Academy of Pediatrics.
Green poop in toddlers is often a sign of a viral infection. This frequently happens when the toddler’s immature immune system meets the developmental milestone of oral exploration.
Diarrhea should be treated with excess fluids to prevent dehydrations. Diarrhea with a fever of 100.4° F or higher (rectal, forehead, or ear) warrants a call to the pediatrician.
Green Poop and Older Kids
Kids often eat foods that have food dyes, including green, purple, blue and yellow, or red and blue coloring. They are found in grape Pedialyte and some kids’ breakfast cereals, drinks, candies, birthday cakes, and cookies.
Green poop in kids can also be due to iron supplements, viral gastritis, or digestive enzyme deficiency such as lactose intolerance.
When to See Your Healthcare Provider
If green stools are an ongoing concern or accompanied by the following symptoms, talk to your healthcare provider:
- Abdominal pain or cramping
- Alternating constipation and diarrhea
- Diarrhea, watery, or liquid stool lasting more than 48 hours
- Signs of mild dehydration, such as dark urine, dizziness, dry mouth, and fatigue
- Any other unusual symptoms
When to Seek Emergency Treatment
If you have black or bloody stool or signs of severe dehydration from diarrhea seek prompt medical attention.
Signs of severe dehydration in babies and children include:
- Absence of wet diapers for four hours or more
- Crying without tears
- Listlessness or irritability
- Loss of consciousness
- Sunken abdomen, eyes, cheeks, or fontanel (the gap between the bones of an infant’s skull)
Signs of severe dehydration in adults include:
- Dizziness or lightheadedness
- Loss of consciousness
- Increased heart rate or breathing
- Muscle weakness
- Unusual fatigue
Stool is normally brown because of how the bacteria in your intestines gradually change its color during digestion. However, green poop is common at any age.
Stool typically turns green because of something green that you ate or drank, and it usually returns to brown within a day or two.
Stool can also turn green if you are doing a colon cleanse, eating something with a laxative effect, or have diarrhea. This is because the stool is rushing through your intestines so quickly that there’s not enough time for your intestinal bacteria to make it brown.