Join Our Thyroid Awareness Campaign this January!

January is Thyroid Awareness Month

Join us this January to spotlight thyroid health. Participate, share, and spread awareness for a chance to win exciting prizes!

Why Is My Poop Green?

Learn if there is a connection between the color of your poop and thyroid function.
Why Is My Poop Green?
Last updated:
Medically Reviewed by:

In this article:

Most of us expect to see brown poop when we look in the toilet. So, it can be pretty alarming when your poop takes on a different color. While there are normal variations to poop color, some of them can be concerning. Fortunately, when it comes to green poop, there is usually a rare cause for concern and almost always a straightforward answer. Here’s what you need to know about green poop.

Causes of green poop


The most apparent cause of green poop is dietary changes. What goes in your mouth often determines what comes out. Green vegetables are the primary cause of green poop from the diet. Chlorophyll, a green pigment that plants use to make food through photosynthesis, is abundant in leafy greens. This pigmentation does not always break down during digestion, so you can often see it on the other side.

Leafy greens that commonly cause green poop include: 

  • Broccoli
  • Kale
  • Spinach
  • Herbs like basil and cilantro
  • Lettuce

Aside from these veggies, other foods can dye your poop green as well, such as avocados, blueberries, matcha powder, and pistachios. 

Don’t be surprised if your poop turns a greenish color if you eat quite a bit of food that is artificially dyed multiple colors, like multi-colored cereals. And, of course, any food with green food coloring will surely resurface on the other side. 


Certain medications can also make your poop green. However, it is not because there are green-colored agents in the medicines, but rather because they change the environment in your gut. Most notably, antibiotics can change your bacterial flora, leading to changes in how your poop looks. 

When you take antibiotics, you may notice a greenish tint to your poop. And don’t be surprised if it also causes diarrhea, as antibiotics generally wipe out all bacteria, including the good bacteria in your gut. As a result, these medications can throw off the healthy ecosystem that helps digest your food. 

Other medications may certainly be behind your green poop as well, including indomethacin (a non-steroidal anti-inflammatory), the Depo-Provera birth control injection, and even iron supplements. 


Surgical alterations to your digestive tract can also change the color of your poop. For example, people with gallbladders removed often have green poop, especially in the first few weeks of surgery because there is an influx of bile released into the small intestine as there is no place to store it after removal. 

Some bariatric procedures that involve the partial removal of digestive organs can also cause poop to change color. 


Infections in your GI tract are common culprits of green poop as well. For example, bacterial infections like E. coli and salmonella, and parasites like Giardia, can alter your gut flora and cause more bile secretion. 

Health conditions

Certain conditions may also contribute to green poop, including irritable bowel syndrome, irritable bowel disease, ulcerative colitis, and Crohn’s disease. In addition, food sensitivities to items like wheat and dairy, along with celiac disease, may also lead to green poop (again, because of an influx of bile). 

When you should worry about poop color

Poop colors can be highly variable because they are primarily influenced by our diet. There is likely nothing to worry about if you have the occasional green poop, as it is most likely due to something you ate. 

However, it is time to see your doctor when it becomes more commonplace and is accompanied by other symptoms, including:

  • Diarrhea
  • Abdominal pain or cramping
  • Frothy stools
  • Fatigue
  • Weight loss
  • Nausea
  • Fever
  • Vomiting

Is there a connection between poop and thyroid function?

Because there are thyroid hormone receptors all over the body, thyroid function certainly influences the digestive system. However, if you have green poop from time to time or even more consistently, your thyroid is probably not one of the primary culprits behind this change in color. Yet, your thyroid function may be behind changes in the consistency of your poop. 

People who release too much thyroid hormone (hyperthyroidism) often experience diarrhea because their bowel function speeds up. On the contrary, those with hypothyroidism often struggle with constipation because their bowel function slows down. 

Studies also show that hypothyroidism is a risk factor for gallstone formation, which can block bile secretion and decrease one’s ability to digest fats. This problem can affect both your poop consistency and color. 

So, if your poop is green, is your thyroid solely to blame? Probably not. 

How to have healthy poop

What comes out of us is an excellent indicator of how healthy we are both physically and mentally. So, suppose you struggle to have bowel movements, suffer from frequent diarrhea, or have unusual stools. In that case, it is probably time to address it and make some changes to your health habits. 

Generally, most people should have 1-2 bowel movements per day. Your poop should be brown (unless you eat a lot of green veggies or other foods that tint your poop green), pain-free to eliminate, and soft to firm in texture. Ideally, the characteristics of your poop will stay consistent day-to-day. However, it is normal to see slight changes based on variations in your diet.

To have healthy bowel movements, it helps to:

  • Drink plenty of water
  • Eat a diet rich in fiber (increase your intake slowly as too much too soon can cause severe bloating)
  • Get plenty of fruits, veggies, nuts, and grains
  • Avoid foods that irritate your stomach (common culprits include spicy foods, dairy, sugary foods, and caffeine)
  • Get plenty of exercise every day
  • If you have hypothyroidism, take your medication as prescribed to avoid constipation

What other poop colors mean

Of course, green is not the only color that may catch you off guard in the bathroom. Your stool can take on several other colors for a variety of reasons. Knowing what poop colors mean can give you incredible insight into your overall health and wellness. 

Image explaining what the color of you poop means with circular colorful icons

Brown poop

This is the normal color of poop. The brown color comes from chemical changes to bilirubin that cause red blood cells to break down.

Green poop

May be from green vegetables, certain medications, infections, and certain digestive conditions.

Red poop

Can be a sign of bleeding lower in the GI tract, like from hemorrhoids, or it may also be the result of red food coloring.

Yellow poop

Often a sign of infection from a parasite like Giardia or may suggest bowel hyperactivity or gallbladder problems. It may also be a symptom of celiac disease.

White or gray poop

May be due to a lack of bile secretion and can also be caused by some medications.

Black poop

Can be the result of bleeding in the upper GI tract or from eating licorice or taking iron supplements or medications with bismuth like Pepto-Bismal.


Share article:

No items found.

Julia Walker, RN, BSN

Clinical Nurse

Julia Walker, RN, BSN, is a clinical nurse specializing in helping patients with thyroid disorders. She holds a Bachelor of Science in Nursing from Regis University in Denver and a Bachelor of Arts in the History of Medicine from the University of Colorado-Boulder. She believes managing chronic illnesses requires a balance of medical interventions and lifestyle adjustments. Her background includes caring for patients in women’s health, critical care, pediatrics, allergy, and immunology.

Read more

Is Paloma Right For Me?

Hypothyroidism is a long-term commitment and we’re committed to you. Schedule a free, no-obligation phone consultation with one of our intake specialists to find out more.

Schedule a call
thyroid hormone for hypothyroidism

Find out if Paloma is right for you. Schedule a free call with one of our health care advisors.

Schedule a Call