What is green poop?

Your doctor may be able to diagnose the cause of green poop by taking a sample of your stool. They'll send your stool sample to the lab to test for the presence of bacteria or other infections.
Your doctor may be able to diagnose the cause of green poop by taking a sample of your stool. They'll send your stool sample to the lab to test for the presence of bacteria or other infections.

Poop (also known as stool) comes in a variety of shapes and sizes. As stool runs through your intestines, it is chemically altered by enzymes (proteins that are chemical accelerants inside the body).

Usually, enzymes turn the pigment of your stool brown, but sometimes it appears green. Green stool is almost always normal, but it may be a sign of infection in some cases. If you have concerns about your bowel movements, your doctor can help you determine the underlying cause.

Green poop is a common problem. While many people expect their poop to be brown, stool comes in a variety of sizes and colors.

If you have diarrhea, your risk of experiencing green poop increases. Diarrhea is loose, watery stool that often causes frequent uncomfortable bowel movements. When you have diarrhea, it travels through your digestive system too fast to process the stool. If your bile (digestive fluid) can’t break down food properly, it can cause green poop.

Many people experience diarrhea, and it usually goes away on its own. But green poop may be a sign of infection if you’re experiencing severe diarrhea symptoms caused by something more serious.

Recognizing the signs and symptoms of green poop is important for treating it and ensuring your body stays healthy.

Symptoms of green poop and infection

If you’re experiencing green diarrhea with stomach pain, vomiting, or fever, the green poop may be a sign of infection.

Your green stool may be a sign of infection from things like:


Salmonella is a bacterial infection caused by eating food contaminated by animal feces. People experiencing salmonella often have diarrhea, stomach cramps, and fever. Some people have symptoms for several days, while others experience symptoms for several weeks.

E. coli

Like salmonella, e. coli is a bacterial infection caused by eating food or drinking water contaminated by animal feces. E. coli can cause stomach cramps, bloody diarrhea, and vomiting. Most people recover from e. coli infections within a week, but if symptoms don’t subside, you should contact your doctor.


Norovirus is a very contagious virus that can affect anyone. You can get norovirus from interacting with other infected people, touching contaminated surfaces, or eating contaminated food. This virus can cause stomach pain, diarrhea, and vomiting. Symptoms usually go away after a few days.


Giardia is a common intestinal parasitic disease. Giardia symptoms could include diarrhea, gas, greasy stools, stomach cramps, upset stomach, and dehydration. If you have giardia, it’s important to talk to your doctor about finding the right medicine and treatment options.

If you have these symptoms, your green poop may be a sign of infection. In this case, you should seek medical care right away.


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Causes of green poop and infection

Anyone can have green stool. The causes of green poop can come from various things, including:


Many foods can cause green poop. The same pigment that causes plants to be green can cause your poop to turn green, too. The most common foods include spinach, kale, and broccoli. Some food dyes can also turn poop green.

Bacterial infection

When your body can’t break down its waste as normal, it can cause green poop. These digestive issues are sometimes due to a more serious underlying infection like salmonella, e. coli, or a stomach virus. If you’re experiencing green diarrhea with stomach cramps, nausea, or vomiting, it’s a good idea to contact your doctor.

Irritable bowel syndrome

Irritable bowel syndrome affects the way your large intestine functions. This can cause stomach cramping, constipation, and sometimes green diarrhea.

Iron supplements

Certain iron supplements can cause green poop. If your body is ingesting too much iron or is having trouble digesting iron supplements, it may cause changes in your digestive tract.

Certain medications

Certain types of medications can lead to green poop. These medications include:

Diagnosis of green poop and infection

Your doctor may be able to diagnose the cause of green poop by taking a sample of your stool. They’ll send your stool sample to the lab to test for the presence of bacteria or other infections. Also, the doctor may ask you questions about your diet, lifestyle, and other possible concerns. If your doctor suspects an underlying condition, they may order additional tests.

Treatments for green poop and infection

You can generally treat green poop at home by drinking plenty of fluids and getting plenty of rest. If you suspect your green poop is caused by the food you’re eating, try eliminating certain foods from your diet to see if you observe a change in your bowel movements.

In some cases, green poop may be caused by a more serious underlying condition. If you are experiencing abdominal pain, fatigue, weight loss, vomiting, or fever in addition to green poop, you should seek medical attention.

Why is my poop black?

The dark or tar-like appearance of poop is a common condition. The medical term for black or tarry poop is Melena. It may happen due to simple reasons, such as a change in diet or certain medications. Sometimes, however, black poop may signify underlying medical conditions. Black or tarry poop may be caused by bleeding in the upper part of the gut (gastrointestinal or GI tract), such as the food pipe (esophagus), stomach, or the first part of the small bowel (duodenum). Bleeding in the upper GI tract causes dark stools as the blood gets digested on its way through the gut.

Thus, if your poop looks black or tarry, you need to consult your doctor to know whether there is an underlying medical condition.


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Causes of black poop

The causes of black poop include:

  • Certain medications, such as iron supplements, activated charcoal, or bismuth medicines like Pepto-Bismol
  • Certain foods, such as black licorice, blueberries, and blood sausages
  • Peptic ulcers (a sore or lesion that develops on the lining of the esophagus, stomach, or small bowel)
  • Abnormal blood vessels in the gut
  • Mallory-Weiss tear (a tear in the esophagus due to violent vomiting)
  • Bowel ischemia (blood supply is cut off to parts of the bowel)
  • Trauma/injury or a foreign body
  • Gastritis (inflammation of the stomach lining)
  • Varices (widened, overgrown veins in the esophagus and stomach, commonly caused by scarring or cirrhosis of the liver)
  • Upper GI malignancies, such as cancer of the esophagus, stomach, or duodenum

Should I go to the doctor if my poop appears black?

The dark or tarry appearance of poop may also imply a benign or severe underlying medical condition. These underlying medical conditions could be peptic ulcers, cancer, and bowel ischemia. Peptic ulcers are one of the most common causes of black, tarry stools. A small amount of blood in the stool may be seen in children. It is usually not a serious sign and may occur due to constipation or worm infestation.

Even if you believe that you have zeroed down to the cause of black stools, you may consult your doctor to be sure of the diagnosis.

Urgent medical attention is needed if you:

  • See blood or change in the colors of your poop
  • See blood in your vomit
  • Feel lightheaded or dizzy
  • Get fever or severe pain in the abdomen
  • Have unintended weight loss
  • Notice that your skin or eyes appear yellowish

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Which foods cause dark stools?

Certain foods may cause dark stools. They include:

  • Black licorice
  • Blueberries
  • Chocolate sandwich cookies
  • Grape juice
  • Beets
  • Red-colored gelatin
  • Blood sausage
  • Red fruit punch

If the dark color of stools does not go away after you stop eating the possible problem foods, you must consult your doctor.

What is the treatment for black poop?

The treatment for black poop varies depending on the underlying condition or reason. If the dark-colored poop is caused by certain foods, stopping those foods will make the condition go away.

If the black poop is due to peptic ulcers, certain medications, such as proton pump inhibitors or PPI, may be prescribed by the doctor. You may also be advised to stop taking spicy foods. Your doctor may perform a procedure, such as an endoscopy (a procedure in which a flexible tube-like instrument with a camera and light source is used to view the inside of the gut), to treat a bleeding ulcer.

Depending on the extent of blood loss, you may need supplements or blood transfusion. If you are taking certain medications, such as aspirin or NSAIDs, your doctor may ask you to stop taking them.

You may need antibiotics or anti-protozoal medicines if the bleeding is due to certain infections.

Surgery and other appropriate therapy may be needed in case of variances and cancer.

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Medically Reviewed on 3/1/2022
Centers for Disease Control and Prevention: "Giardia Illness & Symptoms."

Centers for Disease Control and Prevention: "Norovirus."

Centers for Disease Control and Prevention: "Salmonella Questions and Answers."

Children's Colorado: "Stools-Unusual Color."

Healthy Children: "Green Poop."

Mayo Clinic: "IBS."

Mayo Clinic: "Green Stool."