Why Is My Poop Green?
You can ask the Internet anything you want
— like, how big is the universe? Or what’s
the average lifespan of an Olive Ridley sea
turtle? Or why are sloths so lazy?
But many of you turn to the wisdom of the
Internet to explain what you find in the toilet
According to our friends at Google, one of
the most commonly googled questions in the
world — at least in English — is: why is
my poop green?
And hey, fair enough. We’re all about fostering
curiosity here, and what’s more fascinating
than the human body?
So in order to answer this question, we should
really start with why poop is normally brown?
The brown color of most mammalian feces comes
from a substance called bilirubin, which is
produced by your liver when it processes dead,
used-up red blood cells and prepares them
to be excreted.
The bilirubin is actually made from hemoglobin,
the protein that your blood cells use to ferry
oxygen around your body.
But even though your red blood cells are red,
the bilirubin itself is yellow. And it’s
absorbed by your liver and excreted as bile,
which is yellowish green because of all the
bilirubin in it.
The liver secretes bile into your small intestine,
where its main job is to digest fats, breaking
down lipid molecules into fatty acids. But,
since the bile is on its way down your body
anyway, it’s also chock full of waste material,
including that bilirubin.
So. The fact is, because of all of the bile
in it, your feces actually start out a yellowish
Typically, as your feces travel through your
digestive system, the bilirubin is broken
down by your gut bacteria — those wonderful
microbial minions that live inside your intestines
and help you absorb nutrients while decomposing
These bacteria eat the bilirubin and metabolize
it into a byproduct that’s colorless. But
when that byproduct reacts with oxygen, it
turns brown, forming a pigment called stercobilin.
Stercobilin is what makes your poop brown.
So, if your poop is green, it means it went
through your digestive system too fast, and
the bacteria didn’t have time to digest
your bilirubin into its byproducts.
So if you notice that stuff’s a little greener
after you take a laxative, or have a touch
of food poisoning, or maybe super hungover,
something else might be goin’ on that’s
hurrying your poop along too quickly.
So the occasional green turd is probably nothing
to worry about, but if it’s always that
color, it could mean that your feces aren’t
spending enough time inside of you for your
intestines to absorb all the nutrients you
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