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"

    Sexy McSex's picture

    Less talk about green crap, more talk about splattering the bowl, what the f*ck are these people thinking, I've got diahrea, the product is officially not a number two or a number one, yet not sitting on the seat seems a good idea so it goes all over the floor as well as splattering the bowl and then a quick exit to finish your Chicken Mcsandwich without flushing the toilet so we all no you're a smelly scuttery dirtbag, I've seen this, nearly puked my wonderful veggie burger and had to close my eyes and think of a happy place. these "events" though frightfull at the time do prove wonderfull pub talk and believe me everyones got a come on folks were all human, even the Queen does poos ya know, bye take care now.

    Sexy McSex's picture

    Golly gosh, just had and after thought, it was a sea of brown with no interuptions of white or maybe a pale peach even......this lady didn't wipe!!!!!!! No toilet paper, gosh I'm thinkin her pants must have gone on pretty smoothly after that!!!! God....sorry for the mental picture what can I say I'm an artiste!
    Bye folks, also other interesting topics, stuff you find in portaloos and why don't they make fake poos(that's what we call it in ireland ya know!) yeah anyway fake poos made of chocolate and you could give them as presents to people who really love chocolate and see how long they can resist on the cold dark nights when the've got a craving and no one wants to get up off their arse to go to the shop, of course hidding in the shadows with a camera whould not be a wasted couple of months, i can think of worse ways to get chronic cramp of the knees! tid be only hilarious! If i do say so myself...

    Deez's picture

    I have duplicated this with Fierce Grape Gatorade several times.

    LordTat2s's picture

    Blue corn chips (with yellow cheeze dip) turned my logs blue. And I waited around long enough to see that the water also turned blue. This bright green log seems interesting. Maybe even more so if pocked with bright yellow corn. Hmmmmmmmmmmmm. Send me your poo pics.

    Psychaotic's picture

    DEFINITELY have to try this on my next acid trip.

    Dan's picture
    m 1+ points - Newb

    Did anybody ever get white colored poop? I had it once, I have no idea what I ate. There was brown liquid around it, but the solid part was white, like cauliflower. Any ideas?

    poopmasterflash's picture

    fierce grape gatorade can do it. so yo yall, im a nyc photographer interested in taking some photos of things that arent green crap... like for one thing, im doing a book on girls with hidden tatoos - so if you know anyone then get at me - and if its a tatoo of a peice of green poop, well thats even coola. holla!

    Jill's picture

    Coconut will do this too. I remember eating large amounts of sweetened, dried coconut when I was little (my mom use it for baking), and then having bright green poop afterwards. I always thought it was really funny.
    I'm in college, I'm sure I can find some friends to replicate the experiment. :)

    Belgand's picture

    I noticed a while back that for some odd reason my stool had adopted a green tone. The only reasonable cause (later confirmed by a repition of the same) was eating guacamole. Not exceedingly large quantities either, but some yummy fajitas with guacamole was all it took.

    Gi_Schmoe's picture

    Well now I know why my poop turns green and knowing is half the battle!

    Tito's picture

    I didn't bother reading through everything, so I don't know if anyone has mentioned this yet, but eating a lot of fruity pebbles will also cause your poop to turn green. Grape Gaitorade works as well, but it is getting hard to find (if they even make it anymore?).

    Scat-Kat's picture

    How come you call is poop? Are you scared of the word: shit, or isn't it allowed... and if that's the case, I think you've got more than the colour of your excrement to worry about.


    Ace Rockola's picture

    Well now I had a leprechaun myself a few weeks ago, but it didn't concern me enough to look online for the answer. Now I'm going to be wondering what I ate that week that had blue food coloring in it.

    cheddar's picture

    does anybodys poop turn anything but green? yellow? blue? red would just be scary

    Someone's picture

    Ever digested too much of the Tongue Splasher's gum? The dye in it will turn your poop weird colors, too.

    Anonymous Tandoori Eater's picture

    For all of you who want red poo: I used to marinate chicken in Tandoori paste. Hello, lovely brick-red poo ... for days. Beets will do it, too. But the most amazing multicolor poo I ever saw was after my son (then 18 months old) chowed down on an entire box of crayolas. (OK, the poop matrix was plain brown, but the little chunks of color were just as bright as could be. If I'd known the Purple Kool-aid trick, or the Tandoori Chicken trick, at the time, it would really have been impressively lovely -- confetti colors in a green or red matrix. Your readers are invited to try this. Crayolas are quite harmless. Chew them well, for best results!)

    Jim's picture

    Very interesting and amusiong topic. Thanks for the laugh. I don't think I saw this. One time when I had a nasty cold I drank an entire large (gallon or 2 gallon size) sized orange hi-c fruit drink. The next day I pooped green. It wasn't neon color, but it was definitely green. I also consumed a lot of vitamin C that day (like 2 excessivly sized tablets) so I figured the vitamin C mad it green. Now I know it may be the food color.

    Drew's picture

    Along similar lines, , I was once treated for a bladder infection and was prescribed (I think) 'pyridium' which caused my urine to appear neon, day-glow yellow, actually almost orange colored, and very very bright. I knew exactly where the splatter went! This was in the '70's and at O C fairgrounds Speedway motorbike races on friday nite and everyone was at least half drunk and a long communal urinal EVERYONE stopped (I mean cut it off!) when I started pissing, it was almost worth the pain to see them (and it)

    Dr. Edd's picture

    If you want seriously green poop drink one glass of the green 'Incredible Hulk' Hersey's Chocolate milk. Scared the crap out of me at first. No kidding.

    Awed Aunt's picture

    In her extreme youth (like age 1-2) my niece developed a craving for cigarette butts--no doubt an attempt to look like us cool smoking adults. She would steal them from ashtrays and stash them under the sofa cushions, then return when noone was looking and chow down. Talk about green poop! This was a nice grassy, organic green, well formed, a sign of high fiber content no doubt! God knows what it did to her insides!

    Hagrinas's picture

    When I took my small daughters to Baskin Robbins (a US ice cream chain store) they ordered some sort of rainbow sherbet. The advantage of feeding it to small children is one of proportion; a little goes a long way.

    The bottom line is that if you think a single die is interesting, you just haven't lived until you see what came out.

    I would suggest that you go to Baskin Robbins and get about a quart of this and consume it at once. It will be well worth it.

    Erik's picture
    m 1+ points - Newb

    The dye will do it, but doesn't all that sugar have something to do with it? I used to binge at the Krispy Kreme (I'm past that now), and I'd get green, runny poop.

    Poopie's picture

    OK, but what about pee. I'm sure everyone has experienced the bright neon yellow pee you can get from some types of vitamins.. but is there anyway to get green, blue or purple pee? That would be a neat trick.

    jozka's picture

    an ex girlfriend of mine, who once lived in pittsburgh (home of heinz ketchup) once told me she met a guy who worked at the company, and said the reason they came out with green ketchup, was because they originally tried blue ketchup, but it turned peoples' poop blue. oh shit! i totally would've bought blue ketchup just so it could turn my poop blue. a veritable goldmine...

    KYle's picture

    there i was dressed and ready to go to the gym when i decided it would be a good idea to go ahead and make a quick deposit to ensure when i was lifting no "little friends" came out...and whaddaya know i had the green poops. Scared to death i cancelled my workout and hopped online where i found my answer. I had been drinking Shasta Grape flavored soda and Welches grape soda by the gallon over the last few days...thanks for setting my mind at ease and letting me get back to my work out routine.

    The Shit Volcano's picture
    Comment Quality Moderatorh 3000+ points

    Eat nothing but salad for three days and you will poop green. Take Pepto Bismol and your poop turns black. Eat a lot of stewed tomatoes and/or prunes and it turns red. Minestrone soup gives it technicolor chunks, but only if you get the nasty Campbell's kind.
    As far as pee colors goes, wakko, take vitamin B complex for a nice neon green shade. At least for a couple of days.

    I found Jesus! He was behind the sofa the whole time!

    cap'n crunch's girl's picture

    Dude, I've been living in my dorm off of cap'n crunch... especially the "Oops... all berries" stuff...
    brilliant green dookie!
    It's really a sight... thanks for explaining, so that I didn't have to go home to mama and tell her her daughter shat green!

    Giggy's picture

    I've had some nasty green and neon green shits before. Never really noted what caused them, but I know it was the food I'd eaten. Nice to know about the breaking down of food colors, should be easier to figure out from now on.

    I do, though, have a roommate who loves to talk about crap, literally. Being in our mid-20's it's still funny most of the time, but he can get a little out of hand. He especially likes to talk about the really dark, almost black ones that leave a stain in the bowl, usually swirling it's way down into the abyss. Yummy.

    Personally, the ones I don't like, but like talking about the most are the hiking piles. From way too many carbs, mostly sugars, to get a lot of calories, and burning it all off right away... peanut butter like smoking piles.

    The ones I don't like seeing, though, are after I've had too much salad or other vegetables and a really quick metabolism... sometimes it can be so undigested that I can tell what the food was beforehand, too.

    But now I'm lingering on too long, like the smell after a really labored dropping. Enjoy!

    wakko's picture

    this is a little off topic (still in the area of bodily excretions) but are there any non-harmful ways to turn urine colors? (stupid practical joke) as for fecus, what about colors other than green or red (just in time for the holidays tho!)? can one achieve white, black, gold, or even cobalt blue?

    johnee poo's picture

    For nature lovers, I have a possible all-natural version of this effect. I once went to a grateful dead show with no money and a bag of oranges. I ate oranges all afternoon, all night, and into the early morning hours. When I finally got home, I was perplexed by the bright green log I left in the bowl. I checked it several times to make sure that it wasn't just the after-effects of the grateful dead show.

    badbrad's picture

    I ate a large box of Boo Berry cereal once, and pooped a bright blue turd.

    Kool Aid Man's picture

    (read in a deep low trembling mans voice)I am the man in the big red kool aid pitcher costume all over the world. rrr. I must find a way to stop pooping neon pink. rrrr. Damn you kids and your freaky experiments. rrrr. I will haunt your poop forever. rrrrr. the poop, the poop, the poop is neon green. rrrr. Its a sign of luck for you all. rrrrrr

    Rob's picture
    m 1+ points - Newb

    BLUE GATORADE - I think that was the catalyst for my girlfriend's 3 year old's green poo. She was freaking out about how bright green it was. I went to the Gatorade website and sent an e-mail to ask the dreaded green-poo question. I can't wait for their response. Maybe I should sue for emotional damage and force them to put a warning label on the product. WARNING - drinking excess amounts of Gatorade may cause a toxic green hue in your feces. HHHmmmmm now that I think about it, Gatorade can market this fun and intriguing experiment. Something like - try to get the colors of the rainbow in one single poo and you win a big cash prize.

    Mr Green Poop Machine's picture

    Drank some FIERCE Gatorade Grape Flavored and deposited the loveliest and smelliest green poo I have seen in quite some time. The good thing is that my nose hairs quickly dissolved from the putrid smell so I saved some grooming time to boot! Three Cheers For Green Poo! Hip Hip.....

    The Green Cornet's picture

    Okay, here's an update for your poop report... TGIF (the ice cream store) makes a blue ice cream that makes your face and tongue blue, and your poop bright green. And I mean BRIGHT green. Thanks for posting this info so I don't think I'm turning into a sheep or something.

    The Shit Volcano's picture
    Comment Quality Moderatorh 3000+ points

    Tell me what they say, Rob. I gotta hear this!

    I found Jesus! He was behind the sofa the whole time!

    mick's picture

    After reading this I feel so much better, just a few minutes ago I passed one of these "aliens." I was scared/worried, but after realizing it was the vast amounts of Kool-Aid (grape, cherry, orange, grape berry, etc. that I drank over the past few days I feel okay about it. I have been drinking more Kool Aid than eating actual food. Don't worry I have been eating but mostly soup. It's fast and I just do not have a lot of time. Todays my first day off and I'm writing about my poop, ... sad.

    The Shit Volcano's picture
    Comment Quality Moderatorh 3000+ points

    Yeah, I hear you. I'm snowed in an the only thing I can do is look at stupid web sites. I've been to Poop Report three times already today. At least there's one bright spot in this endless tunnel of white poo. We're supposed to get three more inches tomorrow! AHHH!!!!!

    I found Jesus! He was behind the sofa the whole time!

    Boo Berry Too's picture

    Just wanted to say, my brother and I too ate Boo Berry cereal religiously as children. We would then marvel at the flourescent green poop we produced there-after. Thanks for stirring up some fond memories!

    pooboytoy's picture

    i have had a relazation fter this article. the blueish greenish shite that i ahve had four four days is due o the fact that i have been eating too much frosting from a cookie cake. consumed i guess in its form you can achieve blue poo. that is my theory. unfortunatley i have no more cookie to test such a thought.

    pooboytoy's picture

    o btw its is black frosting that makes this color

    Wendy's picture

    I live in Guam, I decided to eat half of a fresh coconut. I husked it myself. Result: emerald green poo! Thank goodness for your funny and informative site.... I haven't laughed this hard since we got stationed here on The Rock.

    The Shit Volcano's picture
    Comment Quality Moderatorh 3000+ points

    Emerald green! Damn I wish I could experience that. But alas, I can't. I'm allergic to coconut! Fresh coconut result: anaphylactic shock.

    I found Jesus! He was behind the sofa the whole time!

    Shannon's picture

    I was astonished to notice this morning i had the screaming green squits can someone help me get to the bottom of this i didn't eat n e thing green so im just speechless thx

    anonymous's picture

    I went out drinking last night, and this morning a dozen beer and a full box of Fruit Loops later I took a greenish blue poo, I was rather scared but at the same time astonished as I'd never seen anything like this before, I thought I had a vitamin deficiency or something, I was seriously thinking about consulting a physician, but I decided to scour the internet to see what I could find, luckily I stumbled upen your site, now I know there is nothing wrong with me, thank god for a world where within a few minuted and clicks of the mouse you can find about why your shit is blue and read up on people experiences from around the world, amazing isnt it?

    sumer's picture

    GRAPE FAYGO POP... OH MY GOD I THOUGHT I WAS GOING TO DIE... Thanks so much for your site... No doctors needed for me!!!! YEAH!

    MOMMY J's picture


    Jabatam's picture

    well I haven't done any empirical research on this phenomena lol, but I have noticed that when I drink large amounts or cherry koolaid, my shit is a nice deep red the next day

    Fiorela's picture

    Hi , I need help, I have been pooping little bits of green for the last 2 days. I do not think i have changed anythin in my diet. I drank tea yesterday and coffe this morning, but no kool aid.
    i have only eaten ham and chesses sandwiches and tuna, so what could be causing the color of my poo.

    Fiorela's picture

    oh damn , i figured it out, it must bee this gelatin like, purple sweet.

    Post new comment

    • Allowed HTML tags: s:62:"<em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd> <br>";
    • Lines and paragraphs break automatically.

    More information about formatting options

    This question is for testing whether you are a human visitor and to prevent automated spam submissions.
    Image CAPTCHA
    Enter the characters shown in the image.
    To prevent automated spam submissions leave this field empty.