Why Is My Poop Green?

Stool (poop) is usually brown, but it can turn to different colors, such as yellow, black, or green. Usually, yellow or green stools are harmless because stool color is influenced by the food you eat and how much bile is present in your poop. Most of the time, changes in stool color can be explained by diet or rapid transit of food through the digestive tract, such as in people with stomach or small intestine infections. However, sometimes, poop color can indicate more serious health conditions that should be diagnosed and treated.

Why Stool Color Matters

A different-colored poop (non-brown stool) is rarely a cause for concern. For example, bright green poop can easily be explained by food intake, such as eating more dark green vegetables. Green food dye can also make your poop green. Similarly, eating red foods like beetroots or food dyes (red food coloring, red gelatin) can give you reddish poop or even bright red stool.

But sometimes, red or black stool indicates the presence of blood in your stool. Possible causes include intestinal conditions, hemorrhoids, and anal fissures, which can cause bleeding in the lower digestive tract. Red stools, bright red blood in the toilet bowl, or blood on the toilet paper are a cause for concern. These signs should be evaluated by a healthcare provider as soon as possible.

Similarly, pale poop or clay-colored stool should be evaluated. It can be a sign of problems in the biliary system, such as gallstones, cysts, narrowing of the bile duct, inflammation of the liver (hepatitis), or tumors of the liver, gallbladder, or pancreas.

Dietary Causes of Green Poop

Green Vegetables and Chlorophyll Consumption

The simplest explanation for green poop is that green foods give you green stools. For example, eating green veggies can give your stool a green color due to the high chlorophyll (green pigment) in these foods. Similarly, you may experience green stool or black stool after eating black licorice.

Green Food Coloring Intake

A yellowish-green color of stool can be due to yellow-green food coloring, which is commonly found in flavored drink mixes and ice pops.

Medications and Supplements That Can Affect Stool Color

Iron Supplements

Taking iron tablets can turn your stool a dark green color, which can appear almost black. However, you should seek medical attention if you are not taking iron supplements and your stool is greenish-black.

Bismuth Subsalicylate

Black or green stool is a common side effect of taking bismuth subsalicylate (Pepto Bismol, Kaopectate) to treat diarrhea or stomach upset. Poop turning green from this usually lasts for a few days and is harmless.

Antibiotics

Certain antibiotics can change the balance of your gut flora. Some bacteria, along with bile pigment, are responsible for the normal brown color of your poop. By killing these bacteria, antibiotics can give your poop a green color.

Digestive Health and Green Stool

Role of Bile in Digestion and Stool Color Changes

Bile is a dark yellow-green substance secreted by the liver. It helps to digest fats. When food, waste material, and bile travel through the digestive tract, the color of bile pigment changes from yellow-green to brown through the action of digestive enzymes. Bile, therefore, gives stool its normal brown color.

Speed of Digestive Tract Processing

The color of your stool can vary between shades of brown or green depending on how fast food and waste move through your digestive system. For example, if you have an upset stomach and food moves quickly through your digestive tract, you may have green, watery diarrhea. This is because, due to the rapid transit, digestive enzymes don’t have time to break down bile salts and change their color from green to brown.

Find out “What to Eat When You Have Diarrhea.”

Health Conditions That Can Cause Green Poop

Bacterial Infections

Infections such as Giardia can cause changes in stool color, including green poop. Other symptoms include abdominal pain, frequent bowel movements, explosive, watery, foul-smelling, green diarrhea, greasy stools that float in the toilet bowl, nausea, loss of appetite, bloating, and fatigue.

If you suspect an intestinal infection, call your doctor. They may prescribe medications such as metronidazole, tinidazole, or nitazoxanide, depending on your age, health status, stool test results, and severity of symptoms.

Liver and Gallbladder Disease

As mentioned above, bile is a yellow-green fluid that gives stool its normal brown color. Bile is made by the liver and stored in the gallbladder. Excess bile due to gallbladder or liver disease can cause your stool to turn green.

Intestinal Conditions

People with celiac disease have gluten intolerance. Eating gluten can cause symptoms such as stomach pain, gas, bloating, diarrhea, and green stools in such individuals. Check out 4 Benefits of a Gluten-Free Diet.

Digestive disorders such as inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, can also cause changes in poop color. People with these conditions often have blood or mucus in their stool. This can give the poop a reddish, whitish, or greenish color. Read about 11 Early Signs of Gastrointestinal Disease.

If the blood is coming from the large intestine or rectal bleeding, it tends to be bright red in color. If there are dark red or black stools, it could be due to bleeding in the upper digestive tract. These signs and symptoms should be evaluated by a healthcare provider.

Find out: Is Ulcerative Colitis an Autoimmune Disease?

When to Worry About Green Poop

Green poop is serious when:

It cannot be explained by eating green vegetables or green food colorings.
It is persistent and accompanied by other symptoms such as severe diarrhea, abdominal pain, loss of appetite, weight loss, or signs of dehydration.

Other Symptoms to Watch For

You should contact your healthcare provider if you have green stool accompanied by the following:

Severe, watery, bloody, or explosive diarrhea.
Diarrhea that lasts for more than 24-48 hours.
Diarrhea that is accompanied by vomiting for more than 24 hours.
Bleeding from the upper GI tract (blood in vomit).
Red or black poop or bright red blood in the toilet bowl.
Severe abdominal pain or stomach cramping.
Changes in bowel pattern lasting more than two weeks.
Fever.
Loss of appetite.
Symptoms of dehydration, such as dry mouth, increased thirst, and reduced urine flow.
Headache.
Dizziness.
Fast heartbeat.
Weakness.
Chest pain.

Consult a gastroenterologist if you have bright red poop or black, tarry stools. The red color can be from red blood cells - this can be a sign of bleeding in your digestive tract. Also, seek medical care if you have other concerning symptoms (see above).

The Connection between Green Poop and Health Conditions

Some health conditions that can cause green stools include:

A parasitic, viral, or bacterial infection such as Giardia, Eschericia coli, Salmonella, or Norovirus
Inflammatory conditions such as Crohn’s disease or ulcerative colitis (IBD).
Overuse of laxatives
Clostridium difficile-associated diarrhea (severe diarrhea after antibiotic use)

Lifestyle Adjustments and Remedies

Dietary Adjustments for Normalizing Poop Color

If the green stool is a cause for concern, try adjusting your diet. Excluding green foods might normalize your poop color.

Importance of Hydration and Fiber

Fiber and hydration are important to maintain optimum digestive health. Increase fiber in your diet and drink plenty of water to give your stool a natural brown color and make it easy to pass.

When to Seek Medical Help - FAQ

Should I Go to the Emergency Room (ER) If My Poop Is Green?

You don’t need to go to the ER for green poop unless it is accompanied by other serious symptoms. Call your doctor if your green stool lasts for more than a few days and cannot be explained by green foods or green, blue, or purple food coloring.

Does Green Poop Mean Liver Failure?

Green poop does not usually mean liver failure. It can typically be explained by green foods, food dyes, or iron supplements.

What Bacterial Infection Causes Green Poop?

Infections such as Giardia, Salmonella, and E. coli can cause green poop or green diarrhea.

Bristol Stool Chart

You can use the Bristol Stool Chart to perform a self-assessment of your stools. This chart is available online and categorizes stools into 7 types. Types 3 to 4 are ideal stool types. Types 1-2 may indicate constipation and types 5-7 may indicate diarrhea.

Maintaining a Healthy Digestive System

Awareness of Digestive Health

It’s important to educate yourself about gut health, such as by reading this article on stool color changes. It’s also important to be aware of your usual poop color and bowel habits that are normal for you. This will allow you to seek care in a timely manner if you notice any changes in stool colors or bowel movements.

Read about “How to Heal Your Gut.”

Regular Health Check-ups

Last but not least, it’s vital to go in for your yearly physical. Also, be sure to follow your doctor’s recommendations for health screenings, such as colonoscopy. This can help identify problems early and allow you to get appropriate treatment. Preventive health visits are also a great opportunity to ask your healthcare provider any further questions you might have about green stool or poop color changes.