What Causes Green Poop?
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Green poop can be commonly caused by eating certain green foods, an infection that causes diarrhea, bile, or a side effect of medication. In addition, irritable bowel syndrome can cause green poop and stomach pain. Read below for more information on related symptoms, other causes, and treatment options.
Common green poop symptoms
Your poop (or "stool") is probably consistent in color if you take the time to notice. While the shade can vary from light to dark, most people's stool is brown, and doctors agree that brown is the most common color. Green poop, however, isn't always healthy, but it's certainly not a reason to panic. Stool color is determined by a variety of factors, such as diet, medications, and some gastrointestinal disorders. In most cases, green is the least abnormal color, and some even consider it to be on the spectrum of normal stool. Red, black, and white stool also warrant a visit to your physician.
Common accompanying symptoms
It's likely to also experience:
Why is your poop green?
More about stool coloration
The brown color of stool comes from bilirubin, a product produced by the liver when it routinely breaks down old blood cells. Bilirubin then enters the intestines, where it mixes with digested food, enzymes, and gut bacteria. If stool travels through the intestines at a healthy speed, bacteria interact with the stool content and turn it brown. Any changes to this process, such as during illness, can mean that stool is processed differently and will turn out to be a different color.
Diet and medication-related causes
The following are likely causes of green stool due to things you ingest.
- Dietary changes: The most common cause of green stool is eating green food, such as leafy greens like spinach or kale. Food coloring found in certain foods such as gelatin or ice pops can also be to blame.
- Antibiotics: While you may take them for an infection elsewhere in the body, antibiotics also have a strong effect on the healthy bacteria in the gut that process stool.
- Other medications: Certain pain-relievers and over-the-counter supplements may change the color of stool depending on how you digest them.
Causes of green stool due to more natural bodily processes include the following.
- Bile: This substance, produced in the liver and stored in the gallbladder, helps digest fats and is naturally green in color. It is usually broken down in the intestines, but sometimes it remains in stool.
- Young age: Newborns may have green stool in the first few days of life before it changes to a yellow or brown color.
Causes of green stool due to illness may include the following.
- Gastrointestinal diseases: Conditions like Crohn's Disease or Irritable Bowel Syndrome impair absorption in the intestines and change the makeup of stool.
- Parasites: Though uncommon in the developed world, parasites can cause green stool and are possible if you have traveled outside of the country or have eaten raw food.
- Gastroenteritis: An infection that causes diarrhea forces stool to move through the intestines much more quickly than usual, so bacteria in the gut do not have time to digest normally.
Non specific stool change
There are many factors affecting the appearance of someone's stools. Often a variation in stool color and/or consistency is caused by food or medicines. Leafy greens and certain vegetables like spinach and kale can make stool look green. Iron supplements and medicines containing bismuth like Pepto-bismol can turn stools black. It looks like your stool change is probably a variation of normal.
Top Symptoms: black stool, green poop, dark brown stool, red stool
Symptoms that never occur with non specific stool change: tarry stool, weight loss, rectal bleeding, fever
Urgency: Wait and watch
Irritable bowel syndrome (IBS) is a chronic disorder of the large intestine. It is characterized by recurrent abdominal pain and bowel movement issues that can be difficult to treat. Signs and symptoms of IBS are usually not severe or life-threateni...
Normal variation of constipation
Constipation means bowel movements which have become infrequent and/or hardened and difficult to pass.
There is wide variation in what is thought "normal" when it comes to frequency of bowel movements. Anywhere from three times a day to three times a week is considered normal.
As long as stools are easy to pass, laxatives should not be used in an effort to force the body to a more frequent schedule.
Constipation is usually caused by lack of fiber in the diet; not drinking enough water; insufficient exercise; and often suppressing the urge to have a bowel movement.
A number of medications and remedies, especially narcotic pain relievers, can cause constipation.
Women are often affected, due to pregnancy and other hormonal changes. Young children who demand low-fiber or "junk food" diets are also susceptible.
Constipation is a condition, not a disease, and most of the time is easily corrected. If simple adjustments in diet, exercise, and bowel habits don't help, a doctor can be consulted to rule out a more serious cause.
Top Symptoms: abdominal pain (stomach ache), nausea, stomach bloating, constipation, constipation
Symptoms that always occur with normal variation of constipation: constipation
Symptoms that never occur with normal variation of constipation: vomiting
Viral (norovirus) infection
If you ever heard of an entire cruise ship of people coming down with the same “stomach bug,” chances are that was norovirus. Fortunately, norovirus usually goes away on its own after a few days, but is pretty unpleasant and can spread extremely easily. The ...
Normal occurrence of diarrhea
Diarrhea can be an indication of serious illness – especially in young children – but in some cases it has a much simpler cause and can be easily cured.
If there are simply frequent loose stools – three or more times per day – without other symptoms of illness, the most common cause is food or drink.
Overuse of caffeine, beer, or wine has a laxative effect on some individuals. The artificial sweeteners sorbitol and mannitol are known laxatives, as are some herbal supplements and some over-the-counter vitamin and mineral preparations.
Lactose intolerance, or the inability to digest the natural sugar in milk, causes digestive upset and diarrhea.
Diarrhea can cause dehydration and mineral imbalance no matter what the cause, so it is still important to manage it.
The best treatment is to remove some items or supplements from the diet and watch the results. This will show which items are causing the diarrhea.
It's always wise to use any new supplements in moderation so that if the trouble recurs, the cause will be plain.
Top Symptoms: diarrhea, mild diarrhea
Symptoms that always occur with normal occurrence of diarrhea: diarrhea
Symptoms that never occur with normal occurrence of diarrhea: bloody diarrhea, severe diarrhea, worsening diarrhea, being severely ill, ill appearance
Possible early irritable bowel syndrome (ibs)
Irritable bowel syndrome (IBS) is very common problem that affects the large intestine. It can cause stomach pain, cramps, bloating, constipation, or diarrhea. Doctors think that IBS is caused by the brain sending wrong messages to the bowels, such as during times of high stress, causing physical changes. The formal criteria for this diagnosis requires 3 months of symptoms. Therefore you may have an early presentation.
Top Symptoms: fatigue, abdominal pain (stomach ache), nausea or vomiting, stool changes, constipation
Urgency: Primary care doctor
How to treat green stool
In the majority of cases, green stool may indicate a slight change in the digestive system but is not a major concern.
The following measures may be enough to get you through a bout of green stool.
- Keep track of what you're eating: Since dietary changes are the most common cause of green stool, keep a food diary and compare meals to stool output. In most cases, you'll experience green stool in the day or so after you've indulged in that kale salad or green smoothie.
- Review your medications: Prescription labels will often indicate if changes in your stool may occur after taking a certain medication. Over-the-counter medications and natural supplements are among the most commonly overlooked offenders.
- Be patient if you're ill: Most infectious causes of stomach upset and diarrhea resolve on their own with hydration and rest. While your stool may turn green while you're ill, it will likely return to its healthy color after the illness has run its course.
When to see a doctor
If you experience the following, see a physician promptly.
- Diarrhea that does not resolve after a few days
- Stool changes with severe, persistent abdominal pain
- Foamy or foul-smelling stools
- Other changes in stool color, including red, dark black, or very pale stool
- Recent consumption of raw or undercooked food
- Camping or travel abroad
When it is an emergency
Seek help right away if you have:
- A very large volume of stool: Especially if it is dark black or bloody
- Signs of severe dehydration: Such as fast heartbeat, dizziness, or passing out
FAQs about green poop
Can green poop be caused by stress?
Generally, no, green poop is not due to stress. It is most often due to eating leafy green vegetables, green food coloring, or green foods. However, it can also be due to increased gut motility (speed). Food moving faster through the gut allows less time to break down bile, a green substance that the body naturally produces to digest fats. If bile is not digested, poop may appear dark greenish.
Can green poop be a sign of infection?
No. It is uncommon to produce green poop as a sign of infection. However, if an infection causes your bowels to move more quickly, you may produce green poop as a result. As stated in the prior question, fast-moving food may not give bile a chance to digest, causing green (bile-colored) poop.
Why is my poop green when I'm pregnant?
Green poop is generally not used to diagnose any illness. It can occur because of so many other causes, and many of which are normal, that physicians do not use it often as a sign of a particular diagnosis. Green poop while pregnant may be due to iron pills if you have been given them, or if you are eating more or leafy greens.
Does teething cause green poop?
No, teething does not cause green poop. Changes in an infant's diet that occur concurrently with teething, however, may produce green poop. Some parents will introduce their child to green baby foods or more partially solid food when they begin teething, and this may change the color of their feces.
Why does my green poop smell like sulfur?
Green poop can take on a sulfur smell. Sulfur-smelling or foul-smelling stools can be a sign of a gastrointestinal infection, most notably, giardia. Most gastrointestinal infections resolve within a week to 10 days. If your symptoms persist, or you begin to feel weak or are unable to keep fluids in without vomiting, you should see a physician.
Questions your doctor may ask about green poop
- Have you experienced any nausea?
- Have you been feeling more tired than usual, lethargic or fatigued despite sleeping a normal amount?
- Any fever today or during the last week?
- Have you had any changes in your weight?
Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.
Dr. Wilkinson received his medical degree from the University of Pennsylvania and his BA from Princeton University where he was the Editor-in-Chief of the Daily Princetonian. He is currently a resident in psychiatry at the University of California, San Francisco. Outside of the hospital, Jack worked as an editor at The JoongAng Daily of South Korea and a freelance writer.