What causes green poop?

Discovering green poop in your stool can be a shocking symptom and, while it may due to eating green foods, it may also be indicative of many conditions where bile does not break down completely. The MediFind Medical Team has summarized 10 potential causes of green poop below in order from most likely to less likely based on our data. Learn more about how MediFind works here. You can also enter your symptoms into MediFind’s Symptom Checker to receive more customized results.


Green poop in stool may indicate a gastrointestinal illness caused by listeria monocytogenes called listeriosis. Many foods and vegetables can carry it along with a contaminated water supply. Newborns, pregnant women, and adults with weakened immune systems are in particular danger for a more severe form of infection. Find a primary care doctor near you here.


Trichomonas vaginalis may, in some cases, spread beyond the site of origin and cause green poop in stool after a gastrointestinal colonization. In women, the parasite will primarily show symptoms of vaginal discharge or vulvar swelling or itching. In men, prostatitis or epididymitis may occur though they can also be asymptomatic. Find a primary care doctor near you here.

Irritable Bowel Syndrome

Since green poop in the stool is a symptom associated with the intestine, irritable bowel syndrome may cause it when paired with other intestinal symptoms. The syndrome’s cause is unknown but there is likely some relationship with an intestinal infection. In most cases, the symptoms are quite mild but can become more severe if it persists for more than a month. Consider speaking to a gastroenterologist for a possible diagnosis. Find a gastroenterologist near you here.

Crohn’s Disease

A chronic gastrointestinal disease such as Crohn’s can present as green poop in stool due to an inadequacy of the intestine to properly break down bile. This occurs because the condition involves the body’s own immune cells attacking the intestine and colon. Lowered surface area or a lack of digestive cells will mean less bile will break down before reaching the stool. Consider speaking to a gastroenterologist for a possible diagnosis. Find a gastroenterologist near you here.

Myeloperoxidase Deficiency

A gastrointestinal infection, displaying as green poop in stool, may itself be evidence of a genetic myeloperoxidase deficiency. This rare deficiency results in a reduction of immune cells used to combat pathogenic microorganisms that may then colonize the intestine. Consider speaking to an endocrinologist if you frequently experience gastrointestinal infections. Find an endocrinologist near you here.

Pyoderma Gangrenosum

As a consequence of Crohn’s disease or ulcerative colitis, green poop in stool may indicate pyoderma gangrenosum when paired with painful nodules or postules on the skin. This rare autoinflammatory disease occurs alongside secondary infections that themselves lead to gastrointestinal colonization. Consider speaking to a dermatologist if you also notice skin lesions. Find a dermatologist near you here.

Celiac Disease

Green poop in stool, primarily a result of a lack of bile break down in the intestine, may occur due to a hypersensitivity to gluten seen in celiac disease. This autoimmune disorder may result in damage to the gastrointestinal tract, leading to a lack of efficacy in the digestive process. Consider speaking to a gastroenterologist for a possible diagnosis. Find a gastroenterologist near you here.


Although the possible symptoms can be numerous, green poop in stool may indicate a rare disorder called amyloidosis, which involves an accumulation of plaques (clumps of disordered proteins) in a great variety of tissues in organs. This can lead to intestinal malabsorption, as well as liver malfunction, which will lead an inefficiency in the bile breakdown process and therefore green poop in stool. Consider speaking to a hematologist for a possible diagnosis. Find a hematologist near you here.

Ulcerative Colitis

A development of ulcers in the lining of the digestive tract can result in green poop in stool. Called ulcerative colitis, this rare condition is a chronic inflammatory bowel disease that will cause the immune system to attack healthy cells in the digestive tract, which may lead to an inefficacy of bile breakdown and, therefore, green poop in stool. Consider speaking to a gastroenterologist for a possible diagnosis. Find a gastroenterologist near you here.

Wilson’s Disease

A particularly rare, inherited condition, Wilson’s disease results from an excess of copper in tissue, which can damage the liver. Since the liver is one of a few organs for bile breakdown, the remaining bile will appear as green poop in stool. Consider speaking to a hepatologist for a possible diagnosis. Find a hepatologist near you here.

Understanding the Results

These results are based on the most likely conditions for a 45 year old woman who is not pregnant, and is living in the United States. Our data shows that 96% of the time, this symptom is related to one of the 10 most likely causes. Location and age can also contribute to different results. Use our Symptom Checker to add your information and get your custom results.

Not sure about your diagnosis?
Check Your Symptoms

Differences in Age Groups

As a symptom, green poop in stool is quite universal among age groups. It will be more common in children due to their inexperienced digestive systems, which, after a particularly green dinner, will happen just from a lack of complete food digestion. In adults, especially when paired with other serious symptoms, Crohn’s disease and celiac disease are legitimate concerns.

Differences among Men and Women

There is very little difference among men and women when it comes to green poop in stool as a symptom. Digestive problems, in general, are quite universal in how often they occur between the sexes.

Last Updated: December 08, 2022

Published By: MediFind Medical Staff