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

    1603 Comments on "Green Poop: The Implications Of Food Dye On Poop Color"

    DruB's picture

    Two days ago, my boyfriend and I went to Walmart and on their discount bakery rack they had boxes of a dozen cup cakes for sale. Chocolate cupcakes with Halloween BLACK icing. I should have known something bad would happen when the black icing turned our lips, teeth and tongues black! But we laughed it off and ate the cupcakes anyway. I ended up having Chlorophyll green poop. Dark, dark blue-green. So dark that when flushed (as someone else mentioned) that it turned the water blue like there was a drop-in in the tank. Thanks for your site, at least now I know I'm not dying! I have a hypochondriac friend that I just might offer a cup cake LOL!

    Anonymous Coward's picture

    My 2 yr. old had bright green poop, but was in an otherwise happy mood. I figured out it was the Trix swirled yogurt that probably caused this. And not something weird he may have possibly eaten in a sandbox!

    Anonymous Coward's picture

    Seriously. in terms of making your poo green, the winner has to be Gatorade G2 blueberry/pomegranate. I have seen green poo before but NEVER this green, it is truly a thing of beauty lol

    After 3 20 FL OZ of the G2, my poo has gone from green to become almost an aqua color. It doesn't even look like poo anymore, more like a bunch of melted aqua crayons lol

    At first I was scared because I was having extreme stomach pains and thought the two were related. But the pains have gone, green poo remains and I found this site. Now I just laugh my ass off and try to convince my significant other to behold this 8th wonder of the world.

    Maggie Mayhem's picture

    So I took a poo today at work and nearly fainted when the the toilet paper came away neon green. I couldn't figure out if I was dying or had been bitten by a radioactive spider. Thanks for assuaging my worries! I concur with Ace Rockola farther upthread: we should call the Palmolive colored poop phenomenon "having a leprechaun."

    J. Cannon's picture

    Yoplait Key Lime yogurt produces green poop too. If I eat it at night after dinner I notice the next morning the poop comes out green.

    tyler's picture

    The new 24oz blue tilt alcoholic drinks do the trick... drink one your gonna poo blue drink two and your gonna poop out a smurf no joke!

    yoyo biggims's picture

    i agree with tyler, those drinks do turn your poo blue as, fuck me and my friend, had some tilts and were shocked to find out we both pooped smurfs the next day lmfao

    ChiefThunderbutt's picture
    PoopReport of the Year AwardComment Content ModeratorComment Quality Moderatorf 5000+ points

    yoyo, You didn't have any punctuation in your comment so I added a couple of commas for you. I hope you and your friend are cute.

    Dirty old men need love too!!

    How long a minute is depends on what side of the bathroom door you're on!

    Anonymous Coward's picture

    Thank you for backing up what I already suspected. I hate plain water so I've been using those walmart grape single serving powdered drink like mad (to excess of 8 a day) and it's what I figured (it comes and goes when I have enough money to drink something else that isn't water) but it's good to know someone else knows for sure. Thanks

    aka daryl's picture

    its amazing that i experienced the same phenomenon with only 3 bottles (1.5l) of blue powerade, scared the crap out of me when i looked at the toilet though(metaphorically that is)

    daphne's picture
    PoopReport of the Year AwardSite AdminComment Content ModeratorComment Quality Moderatore 6000+ points

    Actually, I don't think this is a metaphor. A metaphor suggests a comparison or description of something by using something else, when in fact, you did poop.

    What you are saying may be closer to a social register or actual irony, because while suggesting that you did not poop, you actually did.

    Anyone else wanna' get in on this?

    .....hugging bunnies since 1969

    .....hugging bunnies since 1969

    Anonymous Coward's picture

    I would say it is more of a pun than a metaphor.

    MSG's picture
    Comment Quality Moderatori 2000+ points

    I think the figure of speech (whatever we may call it) is reversed; he should have said, "The (green) crap (that came) out of me scared me." That would have been literally true.

    I know many or most of us have had a frightening experience, after which we had an immediate and urgent bowel movement, so that something "scared the crap out" of us; but in aka daryl's case the crap came out first, and then the fright.

    Shade's picture

    My father had this issue with blue cake icing, I was skeptical until today, after eating far too many blueberry yogurts, I had a nice, bright green bowel movement.

    My family was wondering what the hell I found so hilarious in the bathroom.

    Anonymous Coward's picture

    Every time I drink Tilt my poop changes colors. There is so much die in that stuff. Thus, I have a growing collection of smurfs.

    Malt Liquor's picture

    I drank a blue Tilt malt beverage last night that boasted it had "certified colors". This morning my poop was bright green. I barely even had the whole 24 ounce can!!!

    worried mum 's picture

    thanx so much for this site. 3 yr old son's poop was bright green this morn and i panicked cause couldn't remember anything he'd eaten that was green, after reading ur site i realised he'd had a bright blue bubblegum icecream yesterday ! panic over thanx

    Anonymous Coward's picture

    Thank you for putting my mind at rest after a green pooh i googled why, found your site and relised that yesterday my son and I had bubble gum flavoured ice cream and guess what? yep its bright blue...ty x

    Zee Moughnia's picture

    My poop was the most awesome shade of green a few minutes ago! I stared for more than a few seconds and thought "damn u blueberry twizzlers" thank God u came up on google, I love this website! Ur poop story is spectacular, and I totally developed a crush on u after reading this! Lol. I'm also super glad I found this before I called my dr's office and made a fool of myself!

    tickled pink's picture

    I drank 3 glasses of powdered cherry pomegranate crystal light yesterday, and today I have been pooping pink. The water looks exactly like the juice before it went down.

    Anonymous Coward's picture

    Thanks for this article.. and uh.. study
    You put my fears at ease.
    Over the past few days I've drunk a few large slushies
    >_> blue raspberry
    and when my poo came out a bright forest green, it freaked the crap out of me (pun intended)!

    Anonymous Coward's picture

    Got wasted om something called "Joose" the other night. I had never had it before and, from what I remember, I was drinking a few different flavors and must have had over a gallon. While the ensuing poop wasn't bright green, there was a definite dark green effect. Why do they put food coloring in something so few people would ever pour into a glass?

    Count Morkula's picture
    m 1+ points - Newb

    Ah so the Booberry turns the poo berries green. Thanks for solving my personal mystery of the day! I recently ordered 20 boxes of Count Chocula, Booberry, and Frankenberry cereal. I couldn't decide which kind I wanted yesterday so I had a bowl of each kind. Today my innards are green. Yellow #5 & #6, Blues #1 & #2, Red #40 - nom nom!

    Anonymous Coward's picture

    crunch berries.

    Butt of the Joke's picture
    l 100+ points

    I wonder what color poop turns to from eating too many fruit loops.
    More people flush than they do wash their hands.

    More people flush than they do wash their hands.

    Eco Li's picture

    You have GREATLY eased my poop worries with this. Recently I'd been having stomach cramps and haven't been eating the world's healthiest diet. I attributed it to the nasty food and left it at that... or I would've if I hadn't taken a peek into the toilet bowl a few days ago and seen that my doodies were GREY-BLUE... but appeared yellow when I wiped. I became concerned that perhaps I had a gallbladder or liver issue, and searching Google on the issue only made me more concerned! After looking here, though, I recalled that I'd made a whole pitcher of some Blue-colored Koolaide (a berry flavor I think) and had been drinking it throughout the week. Apparently, not ALL Koolaides make our BMs green - some change it to greyish-blue, which is the color I had. Thanks for easing my tummy troubles, though I'm still keeping an eye on this one.

    little d's picture

    So for st.pattys day, my job got mini green bagels for us and the customers. The bagels were pretty much dark green, not the light green you see at any other bagel shop. I had about 4 bagels in the span of a 10 hour day. The next morning, i pooped and it was camoflauge green. It freaked me out. I had another bagel on friday night because i was hungry. Today i got a little sick from the food i ate and everytime i pooped, it was the same color green. thanks to this site, i can stop worrying that i have something wrong with me!

    Miss poops-a-lot's picture

    Bought some major brand super-scoop or superman ice cream to bring back the childhood memories and I've been having green poops all day but I ate it yesterday...I poop every morning and boy was I surprised at 6 in the morning to some bright green poops that looked unreal! Glad this site is here to openly talk about our poop :)

    jim gordan's picture

    ...i drank 3 24oz blue tilt 2 days ago & i'm still shitting green......

    Good god's picture

    I owe you so much. I drank a new "blast" drink that snoop dogg just released. Blueberry Pomegranate. Alcohol. Caffeine. And a shitton of blue #5. I woke up this morning and was mortified. I warned everyone I know. Thank you for making me feel so much better about my toilet situation

    Anonymous Coward's picture

    Blue Bell ice cream Krazy Kolors flavor did this, with only one scoop!

    Anonymous Coward's picture

    Ate a whole bunch of those sugar free "ottor pops" flavored ice light that they sell at rite aid. Green for two days now.

    Anonymous Coward's picture

    It is not just Boo Berry. Kaboom cereal used to have the same fun effect.

    MSG's picture
    Comment Quality Moderatori 2000+ points

    This issue has made the Sunday funnies. In "Baby Blues" by Rick Kirkman and Jerry Scott, a married couple is going to bed, glad it's Friday night; but then they think of all that's coming up on the weekend. Thus, even Saturday will be an early wake-up. Wife says, "Well, let's just get as much rest as we can." Hubby says, "Way ahead of you." Little child has obviously just come into the room, and says to his daddy, "My poop is blue."

    There the strip ends, but we are left to imagine the parents having to get up yet again and inspect the blue poop. Very cute, perfectly imaginable; the first time I have ever seen that subject broached so frankly.

    MSG's picture
    Comment Quality Moderatori 2000+ points

    I finally had green poop! Not day-glo green, but a definite dark green with only a slight brownish cast. For Memorial Day weekend I bought us a dozen cupcakes, 4 with white frosting (thick), four with red (likewise), and four with blue (very thick). So far, in three days, I have eaten three of the blue-frosted ones. At first my droppings were grayish-brown; then yesterday they became almost bluish-brown. Today's movement, however, was definitely green--a deep, troubling, ominous dark green. The stain on the toilet paper was a strong, pure, dark green. Aside from the color, nothing unusual about any of the movements. Fascinating!

    Rich Bagwell's picture

    I have the same results with purple gatorade, but not with purple powerade one 32 oz bottle is enough to do the trick

    Anonymous Coward's picture

    SO wait.... If I eat Cap'n crunch Oops! all berries but I take out the blue ones and don't eat them, my poop won't be green?

    Poopin green's picture

    I worked at a factory several years ago where they had coolers filled with sqwincher. It's like Gatorade to those who aren't familiar. One day while drinking grape sqwincher I told a co worker, " looks like another green poop day". He said, " what!!!!". He told me he had an appointment with a dr. cause he was scared there was a medical problem causing his poop to turn green

    Anonymous Coward's picture

    One 12 oz Blue Hawaiian was all it took. Freaked out in my hotel until I read this site. Then I laughed. Neon green...definitely one for the memories of my trip to Waikiki!

    Anonymous Coward's picture

    For the past week I've had loose black stools....did some research on the web and decided I was dying...and have been really bummed since I lost my job two months ago and have no health insurance. After planning my funeral bash, I came across this site-and realized that my black raspberries are in season and I've been eating at least a cup of them a day, plus the delicious cobbler I made. Thanks for a great site! It looks like I'll live to see another day!

    sitaround's picture

    Grape kool-aid and nacho cheese make poop green as the grass, and its from my ass!!

    I ate a bunch of nacho cheese, grape kool-aid and about a pound of asparagus.....greenies!!

    Geewhiz's picture

    Large Sonic Dr. Pepper with blue coconut two days in a row produces bright green poop and possibly some diarrhea effect.

    Mikel's picture

    I stumbled onto this site because I was trying to figure out what in Tang was giving my 2 year old the neon green diarrhea...Now, sadly, I feel better...Guess it's less Tang for him...

    J Castle's picture

    This site has really eased my mind. Y'see, last night I drank a whole fifth of Eristoff Black vodka. I read a review from some British individual (not that there's anything wrong with that) that warned about the heavy dye in the vodka staining lips, tongue and teeth. But it didn't say anything about turning my poo Crayola green. So it was much to my surprise this morning when I unleashed a bowl-ravaging monster and wiped to discover that the TP, instead of being painted the usual color, was instead decorated with a vibrant blue-green. I looked in the bowl and was both puzzled and delighted to see a massive ink-black poop warship half submerged in a dark blue-green sea. It happened again a couple hours ago. I was starting to wonder if my turds would ever go back to normal.

    Anonymous's picture

    This morning I produced a bright green, reasonably firm stool. This caused mild alarm, although because it wasn't a hateful, runny diarrhea I wasn't too worried. Which got me to thinking: What have I eaten in the last 24 hours? Pizza, chicken salad, nothing unusual. Oh, but wait! Wife brought home a large bottle of purple (Welch's) grape soda. I guzzled a goodly amount (sorry, no specific measures were taken). And I got to thinking, perhaps the digestive process added or subtracted color to produce the, um, green effect. To the Goodle we go, and ... Shazam!

    Thank you, poop report, for giving us the straight poop.

    -- Green with relief

    VenusMattson579's picture

    I just let a big one go boom on the toilet. It was not green, but it was pink. Im freaked out, can you help me? Please...
    cafetiere nespresso

    Anonymous's picture

    I went to Cedar Point yesterday and succumbed to my hankering for a blue raspberry Sno-Cone. Thank you Dave J for posting this article on the poopreport. It is comforting to know something is not wrong with me. It makes me giggle thinking about all the people I saw yesterday eating the blue raspberry Sno-Cones who also are probably surprised with their bright green poo today.

    Anonymous's picture

    even happened with a blue velvet cupcake. yikes.

    Anonymous's picture

    I had the greenn poop happen to me this morning too. Well I thought maybe I was sick on the inside and didn't know it. So I thoght I will check on and maybe get some answers and I did this report helped tremendously!!! I ate cake with blue and green icing last night and there is the food coloring that made my poop bright green. At least I know now what it could be and I'm for sure cuz I was fine before this crazy shit!!! Lol. Thank you, paty

    Anonymous's picture

    It's good to know nothings wrong with me!

    Anonymous's picture

    has anyone have had the green color bleed from the poop into the water? almost like green paint dropped in.
    I had some superman icecream yesterday. along with some red koolaid and i think this may be the culprit but ive had some intestinal issues in the past.

    Anonymous's picture

    Yesterday I had a blue frosting cupcake, this morning my poop was GREEN... I was like what caused it and you just answered it. the Food Coloring. Thank you.

    cruelolive's picture
    m 1+ points - Newb

    I remember that when I was a kid whenever I ate pickle flavored potato chips my shit would always turn a nasty green color. Couldnt tell you now, though.

    How many times do I have to flush before you go away?

    MSG's picture
    Comment Quality Moderatori 2000+ points

    Yes, indeedy, J Castle, a day or a few days after you lay off the black vodka (!), you will poop brown again--unless, of course, you ingest something else with strong coloring in it. I wonder what your vodka would produce if you had beets as part of the next meal. If you try that, let us know.

    Anonymous's picture

    We look to see if we don't need to look any more (that our butthole is 'clean').

    Or to feel proud and think "Wow, look what I just did."

    Anonymous's picture

    I can't figure out how to leave a comment, so I'm 'replying' to yours.

    Anyway, I had an ugly green poop this morn. Looking around as to what causes greenies, I found this article and realized I had been drinking a bunch of this cheap-o dollar store THIRSTEE grape mix. It used Blue 1 and Blue Lake 1...unlike the Blue used in the experiment. I wonder if that makes a difference?

    Anonymous's picture




    Anonymous's picture

    I'm very in touch with my inner rectum and can predict which foods will turn my fecal matter which color. In some cases

    I have even used a fecal sac to help turn my feces different shades in order to have different bio paints.

    If this website was sold , well hell new owner. Im the_shitman and im here to deficate on your forums. btw im never going to leave. ive been comming here 9 years.. just ask dave and dappy doodles

    Anonymous's picture

    Grape Crush soda... YUP!!! Green Poo!!

    Anonymous's picture

    Thank you for this site.... I was a little worried this morning after my morning bathroom trip. I had a really loose stool after overeating more than likely but to my shock it was St Patty's Day in the bowl. Not slightly green but GREEN.
    I have had greenish stools after eating spinach or other greens but this was different. Enough to make me check the net.
    The culprit... a 32 Blue Rasyberry Slurpee kind of thing from a gas station! It was good going down and now that I am not concerned kind of fun coming out ;)
    thanks and I think I might buy my girlfriend one just to see her shock.

    Anonymous's picture

    Three cans on Anheuser Busch "tilt" (blue can) in the evening, greenish-blue poop the next late morning. Thought I ate a "Smurf" in my sleep.

    Anonymous's picture

    i don't flush the toliet

    Anonymous's picture

    I wonder if mine was the neon worms (I love the blue/red ones). I didn't have that many but it's happened the last few times I ate them. Glad to know I'm not abnormal.

    Anonymous's picture

    lol all I did was eat a cookie cake with blue icing on it. Thanks so much for this. ahah I was like what the crap, this is green!! What's wrong with me!? Good to know the answer is nothing.

    Anonymous's picture

    Blue Hawaiian Cocktails :)

    Tasted great on a hot summer's eve, but caused some concern the next morn.

    Anonymous's picture

    Ive been eating giant eagle's value brand of twizzlers...and only the blue and green kinds... and they have been on super sale.. so ive eaten "alot." And well to say the least ive been shittin bricks thinking something was horribly wrong. Its a classic neon tennis ball green. But now its all starting to make sense. Thanks doc poo

    Anonymous's picture

    My 3 year old son just got off the toilet and said "my poop is green!" I had to look. It was actually half brown/half green. I thought for a minute about what he had eaten yesterday. Then I remembered the blue ice cream he had last night! This website confirmed my suspicion. Thank you!

    Anonymous's picture

    09/20/2011. Drank a bunch of 'purple' flavored store-brand beverage powder over the weekend.

    Produced Lime to British-Racing tones of green. Scared the, well, that, out of me. Suspected the purple drank, but wondering why it would be green and not purple. Googled, found this page, feel alot better.


    Anonymous's picture

    Amazing, isn't it. I had similar

    During the summer months we would get lemon ice a couple times a week. I love the blue raspberry.

    Had noticed a change in color for the past month. Started to really get worried and finally found this website.

    Have since decided no more Blue Ice for me. Thanks

    Anonymous's picture

    Eight 16 oz. bottles of blue Gaterade in two days = GREEN POO! and runny at that :(