Green Poop: The Implications Of Food Dye On Poop Color

l 100+ pointsm 1+ points - Newb

Editor's note: here's the short answer -- blue food coloring turns your poop green. Keep reading to find out more, and then peruse the many, many comments for corroboration.

Since my freshman year in college (a small liberal arts college in
northern Vermont), I've been fascinated with the correlation between the ingestion of
food-coloring and the color of the poop produced. Lest you think I'm fabricating, here's the background:

The year was 1996. I was a biochem major at St. Michael's College in Winooski, Vermont.
I had consumed copious quantities of Purplesaurus Rex
Kool-aid in a one night time frame. A few hours later, I pooped. It was
green. Bright green. I was fascinated, and called as many of my
floor-mates as would come into the stall to marvel at the miracle of the
"not brown, not bloody shit".

I was a bit of a celeb for a while, until others replicated my
"experiment". Similar results ensued, with me being notified of each event
via e-mail. So, a craze started.

As the progenitor of the new species of poo, I was caught in the middle. Research spread far and wide; of
a campus of 2700 students, I was receiving up to 45 e-mails a day from

Anyway, enough drivel. Here's the science:

The dye used in purplesaurus Rex is FDA Blue #5, and dye-lake
red. Turns out that when metabolized in sufficient quantity, the blue dye combines
with bile, and forms a brilliant green. The red, absorbing at a 595nm
spectrum, is harmlessly eliminated.

What matters is quantity. I consumed 6
liters of the Kool-aid in the night in question (sans alcohol, that comes
later). I set up a study in the dorm, with people consuming anywhere from
(1) 250mL glass of the stuff (approximately (1) 8oz glass) to the maximum tested
so far, 6L. The experiment was structured on a single-blind study (won't get FDA
approval, but sufficient), with only myself knowing what each was consuming.

How did the experiment come into being, you might ask? Well, I campaigned for 24 "volunteers"
(the first consuming 1 glass, the last consuming 24 glasses). How did they
not know what they were drinking? Well, since it was only single-blind,
they essentially did -- though all were required to drink 6L of fluid total,
and ordered not to defecate at all in the 6 hours of the experiment.

Example: Subject 1 received 250mL of the subjected test substance, and
5.75L of water. Subject 2 received 500mL of the stuff and 5.5L of water.

Everyone was agreeable at first, but soon dissention reigned prime. But order
was maintained. After 6 hours, orders were given to poop, supervised (more or less).
Since I had unrestricted access to the chem and bio labs, samples of each
"extrusion" were taken, in the amount of 2g.

The results were heartening. I plan on getting a PhD (which, in this instance would probably mean, "PUSH
HARDER, DUMMY!") on this someday, so I won't post my final data, just enough
to give an idea:

  • Subject 1: 250mL Purplesaurus Rex with 5750mL water:

    Stool, firm and brown. Spectrophotometer reading: normal.

  • Subject 12: 3000mL Purplesaurus Rex with 3000mL water:

    Stool, firm(ish) and green(ish). Spec reading 550nm (definitely Green...just not GREEN)
  • Subject 24: 6000mL Purplesaurus Rex with 0mL water:

    Stool, Firm(ish) and
    Green, resplendent of original test subject (me). Spec reading, 535nm. Definition of GREEN confirmed.

  • Further experiments considered fruit punch (mostly synthetic, only 2.5%
    fruit juice), Hi-C of various persuasions, and various and sundry other
    store-bought concoctions.

    If you're interested in my results, let me know...I'll gladly share them for
    the good of society.

    -- Dave J

    On May 27 2003, received this email. Dave J, the author of the above piece, was so happy that he wanted this added to his story as proof that writing for PoopReport can improve people's lives.

    dear poopreport,

    i know you may find this hard to believe, but you just eased my mind tremendously about our daughter's "poop situation." beginning yesterday about 5p.m. our daughter began having bright green dirty diapers. she has had four in a 24 hour period and i (being an over paranoid mom) have contacted everyone i know, including our pediatrician, and no one had any answers other than it will probably go away. that response just does not cut it with me. i had to have answers. i have been on-line non-stop trying to dig up a possible answer. i told our doctor that the only new food or drink she had consumed was "purple kool-aid" and lots of it. he told me that purple kool aid would not produce green stool. after reading your article i realize it can. thank you soooo much. after hours of searching and worrying, i am off to bed.

    -- grateful mom

    1629 Comments on "Green Poop: The Implications Of Food Dye On Poop Color"

    buckfifty's picture

    Fanta Grape Soda, drank a 2 liter bottle in 2 days. Blue Dye #1 Scary... Try eating a meal of corn and fanta!

    buttnugget's picture

    I once had a poop that was red and green like Christmas colors.

    DorkPoop's picture

    I have to say that cake icing also has the same effect. I had birthday cake yesterday with Blue icing. I really did not consume a large amount, but my poop was very green. That was the only thing I had that held food dye.

    DorkPoopAgain's picture

    Oh- yes I just read Ricky's message about blue cake icing- and yes, mine was from WalMart also!!!

    the dogg's picture

    thanks for helping with a potential shitty situation. cheers to the koolaid

    Poos for life!'s picture

    This site is great! I've been having green poo for a couple of days now and have been wondering what was going on....I've been eating red licorice for the past two days! Thanks Poop Report.

    Excellent Turd!!'s picture

    This morning, after me daily 10am shitbreak, i had to take a good long look at this. Felt like I had given birth through my ass. McDonalds for breakfast AND lunch yesterday, along with mass amounts of FierceGrape Gatorade.. This shitstick was AWESOME!! It started out a nice rich brown, fading into a great bright green!!! GREAT consistancy!!
    WISH I had my camera here at work. I plan on repeating this recipie though. This is a must try to all of you who haven't!!
    Rock on PoopReport!!!!

    Crackle's picture

    I am puzzled. Went to the can and had some nice green poop. I thought wtf is going? Hopped online and found this. Interesting site! I really dont know what gave me this. I havent had anything with crazy food colouring, from what I could see.
    I had A&W steak burger for lunch at around 1pm today..its not 1 am. Not sure if thats it or not. Ive drank quite a bit of coke in the last 24 hrs although I have done the same in the past but havent experienced anything like this.
    Very strange, but glad to see nothing is wrong with me ;)

    Eekorama's picture

    Your green poop website saved me emotional anguish like the mother who wrote you that letter you posted! I was thinking, "oh my God!!! what kind of tropical bacterial disease do I have!?"... then I found your website and set my mind at ease when I remembered downing a 2-foot long super straw of brightly dyed sugar from a theme park a day earlier.

    Thanks Mr. Poop!

    Fred E. Smith's picture

    not my real email address for privacy concerns, but must say I had been drinking Fierce Grape Gatorade for 3 days due to kidney doctor's recommendations...and became alarmed, considering I have kidney disease when my poop turned the brightest green I have ever seen. I called my Nephrologist on friday out of concern for the color of the poop, but he offered no answers...thank God i found this website, as my concerns were aleviated and the mystery solved with the obvious connection made between my fierce grape gatorade consumption and my fierce green frighteningly smelly excrement! Thanks poopreport, I'm recommending you to all my friends!

    new kid on the pooper's picture

    I had my first red velvet cupcake two nights ago. Lo and behold, that night I pooped red nuggets. It was literally "Clifford", the dog, red. At first, I thought it was blood but later realized that each turd was too uniformly red. There was no way that it could be blood. Man, the effects of red dye!

    Brian's picture
    m 1+ points - Newb

    My poop was green today. I suspect it was the bottle of Gatorade fierce grape flavor that I consumed last night.

    Otis's picture

    I ended up at this page today after wiping my ass about 5 minutes ago... Well, I then did a google search to find out if I might have some sort of medical problem.
    Thanks to this page I now know that it's due to the Boo Berry cereal I was eating yesterday in celebration of Halloween.
    I just want to say thanks to
    I can now move on and have a productive day

    Slushie Lover's picture

    After taking a dump yesterady I noticed that one of the logs was half brown half green. I shrugged it off until today when everything was green! A quick google search brought me here and reminded me of the large blue slushie I had two days ago. Thanks for putting my mind at rest!

    Alex's picture

    Well for the last few days my poop has been a very bright color of green and i did not know why. I thought it was becasue of the food i was eating but tonight after reading i found out it is becasue i have been drinking Grape Gatorade for the last week. About a gallon a day. So thanks for the info.


    Carla Ondi's picture

    I'm hoping my daughters poop is dark green from the coolaid she has been drinking. She hasn't had the coolaid for about two days, but has been drinking Oceanspray grape and her poop is still dark green. Can the grape juice also make her poop green?

    Leigh's picture

    Wow, I did the same thing as like...half of these people here. Went to Moe's two nights ago, had like...3 glasses of lemonade. Went home, used the restroom. Slightly green. I was like..freaked out, but just blew it off. Yesterday I went to Moe's again, had a lot of lemonade again, completely green. Thanks for easing my mind.

    Crakrjak's picture

    Believe it! Pitch black's blue #1 dye has turned my #2 as green as my lawn, And smells akin to rancid grapes. I did some research and blue #1 has been banned in several countries, before now i was never concerned much about food additives. Now i'm wondering about what is really in the foodstuffs these companies throw on the market. I'm hoping this side effect does not last very long.

    Mal's picture

    At the University of Oklahoma there is a Blue Bell ice cream shop conveniently located at the bottom of my dorm. There was a new flavor in stock known as Krazy Kolors, how could I resist this beautiful swirl combination of red, blue and yellow. I tried a sample and knew at that moment I had to get a scoop of it. The next morning I woke up with the overwhelming need to poop. To my amazed wonder the snake in the toilet was not the normal brown but more of a blue-green shade. I immediately ran to grab my flashlight to get a better gander at this "eighth world wonder" if you will. It was definitely blue-green, so I sprint down the hall shouting at the girls to come see what my blue-bell-bottom had produced. I think there might have been some jealousy and pretty sure a few girls went to try this blue-bell experimentation. My warning to you is to beware of Krazy Kolors ice cream, it may seem like an innocent new vanilla but IT IS NOT!!!!!!!!!

    Pooper's picture

    I ate a ton of M&Ms and shit bright green. Talk about frightening. Thank God for this site!

    poopochondriac's picture

    Today, I got home and bee lined straight for the potty. Well, let me tell you, I was astonished to find a spinach green stain on the T.P. When I looked in the loo the little green monster was stairing back at me- I thought it was the lighting- so just to make sure I took a T.P. stained sample out into the hall to get a better look! When it really was green I thought I was going to drop dead of some green poop causing disease right then and there! Well straight on the internet I went-after finishing the dirty deed- and I found this site. At first I was still worried as I don't drink Kool Aid. And then I saw those Devious Lucky Charms with the new green clovers mentioned. As it turns out I was eating not bowls of them last night, but just picking out the marshmellows for a sugary treat... Oh sure like you all haven't done the same before!!! Thanks for easing my anus... I mean mind!

    boby the turd's picture

    i like takn poops if any one else does call me at 1-563-556-0702

    random pickle's picture

    well im getting green poo and i dont know why please can sum1 tell me and i havent been havin purple cool aid

    random pickle's picture

    dont email me da answar

    joe peeboo's picture

    actually could no one email me their answers? Thank you. J.P

    joe peeboo's picture

    Just kidding! You can email me anything you like. ANYTHING! And by the way I just did some more green poo. Probably because I stuffed a whole truck full of green cordial.

    poogirl's picture

    i just pooed GREEN. like, not just green but GREEEEEEEEEEEN. so i got worried and googled "green poo" and got this site. turns out that last night i drank 5 glasses of purple kool aid mixed with blue curacow.

    hence pooing green. thanks.

    Luig's picture

    The email adress is not real to protect my privacy. I have the green poop and believe I have traced it to sunflower seeds. Does anyone have a similar experience?

    Kris's picture
    m 1+ points - Newb

    Lucky Charms will also turn your poop green. I noticed this last night, and did some research on the subject and found this site!

    aurora's picture

    i went out last night, drank WKD blue and shots of black sambuca. one or the other is the culprit, but my green poo's still quite scary!

    joe peeboo's picture

    I keep getting green poo. I really should stop,eating grass, drinking the whole drink machine full of green drinks. Look I'm surprised i haven't actually turned green yet!

    king of my Hill's picture

    My brother and I used to do this by mising food coloring into our strawberry quik with our friends- then everyone would run to the toilets- different colors all around! Plus, you can get Boo Berry and Franken Boo seasonally at Target- NOW I know why we spend every Oct- Nov green- I buy tons of it for $2 box!!!

    Kelly's picture

    A friend and I ate some St. Patrick's day cookies, sugar cookies with green icing, and both of our poop was green the next day. I'm glad to see we're not alone.

    Green Poopy's picture

    Sonic has a blue drink called OceanWater, causes green poop!

    Ed's picture
    m 1+ points - Newb

    purple powerade = green poo

    Bug's picture

    i came to this site after eating over a whole bag of Brach's peppermint nougat Christmas candy - what's the logic in that turning my poo so green?

    Danielle's picture

    Today I gave my child grape (purple) gatorade all day to to diarea and I changed his diaper this evening and found floresant green poop. I freaked out. I discribed it as pea soup to my husband. But now I know it was because of the gatorade LOL. Thanks for the interesting article :)

    Something Fierce's picture

    Wow... I see I'm not alone in the universe! I just had a green (British racing green) poop, and thought there must be something wrong with me. A quick search brought up your site, and set my mind at ease. As I type this, I am looking at the same empty 64 fluid ounce bottle of grape Gatorade Fierce that I polished off this morning. Yup, the culprit is right here... still on my desk!

    Green Turd's picture

    luckycharms my ass

    they bring you green shit not gold

    John Rice's picture

    Hmm, last night I drank about 24 ounces of grape gatorade and didn't think it was the result of my green poop. But after reading this page it makes sense. I consider my investigation complete. Thanks

    Blueberries. Who knew?'s picture

    I do not drink anything other than coffee and water, so the koolaid is a nix for my green poop that had me perplexed today.---BUTT after further investigation, I determined the fecal discoloration was due to the large mass of blueberries I consumed this morning for breakfast. It was a part of a fruit salad, and the juices had all turned dark blue from the blueberries. Now I know, and I hope that my more organic experience has been a pleasure to read about.

    the art of colors's picture

    I am an artist, as my name suggests, and it was not surprising to me to hear that consuming blue liquids makes your anal excriment green. when you mix blue and brown paint colors, you end up with a green...varying on the amounts of blue and brown--different shades of green. granted, it's more of a poop green. =] I guess our body is more predictable than we think. I challenge the world to continue on in their experimental bodily creations--drink blue--drink red--drink orange---try yellows---try blacks---and create---life without art is so brown. do not conform to brown. I call you to color the sewers! surprise the mundane crap out of alligators---and most of all, dare to make this world beautiful once more.

    Licorice Lover's picture

    Hey, That has never been explained to me! Yes, licorice dumps a oddly coloured green. I seem to have the only family that corn is a laxitive though. Brown with yellow speckles is also a site. :)

    Neon Green's picture

    I took the green dump to end all green dumps..even the water in the bowl turned green...I thought I crapped an alien or something..not quite sure what is to blame tho..maybe blue go-gurt?

    crazy white dude's picture

    i have a question that perhaps someone will try as an experiment. if you eate nothing but marshmallows and drink milk for a week, will your poop come out white?

    pregnant chick's picture

    I am pregnant and have been having green potty issues since around the time I found out. I finally went online out of curiousity and figured out it was the extreme grape gatorade I have been drinking to stay hydrated. How humorous :) Thank you for posting this site for all of us knuckleheads.

    Me!'s picture

    Yikes, been drinking Hawaiian Punch Bodacious Berry and my poop turned greenish blue.

    They should really have some sort of notice to tell people not to freak out, because I certainly did.

    Joy's picture

    My son had the flu and had not been eating. All he had was blue gatorade and orange jello for close to two days, and he threw up green mess! Nice to know there is a scientific explanation for this.

    Cocytus's picture

    juz pooped with all my might... when i had actually tot its juz diarrhea, it turn out to b green poop... amazed at first. but after reading this web, i'm rather at ease...
    my parents told me tt's its due to fear.. which explains y as i've been having weird dreams e past few days.... BUT, after reading through ur webby, n after thinking back wats my diet for e last week... i'm sure its e food more den my tots...
    my diet for e week consist of, papayas(bout 2 full size 1kg+), bananas(a bunch), lots of vege n 3 litres of milk... all in 5 days..

    Poopster's picture

    I can confirm that eating 5 or more strands of "Blueberry Licorice" will also produce the desired green poo.

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