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

    1619 Comments on "Green Poop: The Implications Of Food Dye On Poop Color"

    Matt's picture
    m 1+ points - Newb

    After c*apping dark green 2 days in a row I did a search and found this site like everyone else. I hadn't seen my cause mentioned so I'll add, I think my case was caused by the yummy Italian striped cookies that are usually red and green with a thin chocolate top. The ones I had this time were all green striped, causing dark green poo.

    SD's picture

    Wow...I am amazed that other people out there are, just like I am, typing "bright green poop" into their search engines! Lol. I was quite alarmed to find a very bright green poo after going to the bathroom this morning. After reading this, I am thinking back to the red and blue (for Memorial Day coming up) rice crispy treats that I had yesterday. Red + blue = purple. Whew, am I relieved!

    bob's picture yeah, i probably had about two shots of green food coloring last night (dont ask its a long story)..and yeah sure enough, my poo was about as GREEN as can be...for about 1 second, i was "wtf!?" but then i figured it out....

    Rach's picture

    Umm...first of all...I love how we all googled "green poop" and found this place. It makes me smile on the inside. I seriously like 10 minutes ago pooped bright green poop...and I have a severe version of Irritable Bowel I know all about the poopies...however...I've never had such bright green poop in all my 11 years of having ol' IBS. So I googled green poop...and it's amazing...I guess it was the purple gatorade. Weirdness. Anyways...thanks for the help poop site...I'm coming back here more often!

    Fey's picture

    Sonic's blue Ocean Water drink will produce the same effect, as will purple soda.

    Kiliki's picture

    Don't know whether it was the massive amounts of jungle juice or the black & orange frosting off a graduation cake that was consumed, but my excretion definitely was neon bright I think it actually glowed in the bowl. Thought I was dying so I decided to type the highly intellectual words "green poop" into the search box & was relieved to find my diagnosis was simply a result of food coloring.

    :auri Jean Crowe's picture

    Dear Dave - Thank you for your enlightening work on green stool. My son is in an acute nephrotic state and heading toward renal failure. To control his electrolytes the docs prescribed gatorade as my son detests the taste of pedialyte. His stools have become a vivid and nearly odorless green. At first docs wanted to test for rotovirus, and put the poor kid through the mill -- but I explained, it wasn't the smell of roto and was further told it could not possibly be anything he was ingesting as we have a strict food record. Low and behold, my son will only drink grape (Blu 1, Red 40). So, you have saved my 6 year old son who is having a very rough time of it from having needless tests(he has so much edema his scrotum is the size of a grapefruit right now and he can barely walk). So, thank you Dave! Not only have your provided clues to the mystery, but you have given a child in pain something to help make him laugh - and eased a mom's troubles at having to force him to drink. You see, he now wants to mix flavors to see if the combination will create different shades of poop! He is 6 afterall!! Have a wonderful day - you've made mine better. LJCrowe

    middleagedwoman's picture

    Wow, I've been having problems with this for a long time and had no idea it was due to drinking grape koolaid. Sure glad I found this web site. Thanks.

    scarface!'s picture

    It just hit me, and i was started to really get woried,

    IT MUST BE THE BLUE POWERADE, i've been drinking it the last few days.

    I used to drink blue gatorade, no prob, its also a lot lighter blue

    so my guess is thats it, i'll go back to gatorade to see if i'm right

    Brandon's picture
    m 1+ points - Newb

    my poo was red today... the night before i ate a smallish bowl of strawberries id say 3-4 cups equvilancey but ive had strawberries before and its never happened....

    powerade's picture

    Blue Powerade made my poop green too. I was worried about it until I found this site.

    JOe Dirt's picture

    I work at an Ice Cream Shop, we have bubble gum and superman ice cream, and boy, green Shiet.`!!

    megan's picture

    hey...well..when i pooped and i wiped it, it was bright green and the day before i hahd fruit punch. Could that have caused it? The next day i didnt poop at all...should i be concerned?

    Trisha's picture

    My baby sister graduated from High School last weekend. The school colors were black and yellow. Being a lover of cake and icing, I ate lots of black cake icing. My poop has been BRIGHT Bluish-green for 4 days now... it is definately wierd!!!

    Michelle's picture

    thank you for saving me a lot of worrying thinking that I may have some incurable illness

    J Fitch's picture

    I found a few years back while I was somewhat addicted to "queso fresco" cheese wheels you can find at most grocery stores that if you eat at least half or more of the entire wheel in one sitting..which isnt that hard compared to other cheeses. The next day you'll have a perfect WHITE POOPIE. It's awesome you get great food and spectacular poop. everyone should try it. lol =)

    Kurtis Pauly's picture

    I had green poop after drinking bottles of kool aid with my boyfriends in the san diego area. I thought I was catching some homosexual disease but thanks to this site, I know better. This is amazing.

    Anne's picture

    We had a graduation party yesterday, and as I was the one cutting the cake, I ate a lot of blue icing. This morning I took a poop in a dark bathroom. Even in the dark I could tell something was off. I turned on the light and jumped! WOW! That is really green! What disease do I have? Did I drink on glass of wine too much? I tried to get my husband to come and look,but he just looked at me. So I googled "green pop" and found your site. Bless you, bless you, bless you!

    Nicole's picture

    that still does not anwser my ? cause i have never heard of that drink and i get green poop every once in a while so other things must do it 2

    concerened Dad's picture

    My 8 year old had bright green poop today . Just realized I bought him a darth vader ( dark blue ) ice cream cone at the ice cream truck ! harmless but he is releived ... pun intended..

    Mdhatter's picture

    First, phew.

    Second, I work for a copmany named "GREEN", and I thought maybe I deserved a promotion after last-night. eat, breathe, and ......

    So, allow me to add Purple Gatorade to the list of offenders, and that it is more effective when one is dehydrated.

    I see a brilliant practical joke in this.

    mugu dey's picture

    I dey here o!!!

    Jason's picture
    m 1+ points - Newb

    Does Red kool-aid turn your poop redish color ?

    Tom's picture
    m 1+ points - Newb

    Well.. I was quiet surprised to find my poo looking Green.... But I soon found out why by going to the wonderful So if u dont want green poop, dont drink Grape Gatorade

    Louie's picture

    This is the longest tribute to green poop that I have ever seen.

    Jason's picture
    m 1+ points - Newb

    Well...Today i went poop and low and be-hold it was bright green scared the heck outta me.I couldnt think of what i may have consumed to turn it green. I typed in green feces and BAM this sites pooped up oops popped up...If it wasnt for this site i would have been heading to the doctors or the ER...Thanks for saving me the trip and a painful rectal exam... :)

    Lokee's picture

    My my daughter had a bright green bile movement. I thought it was something seriously wrong. Until I read your site. That's when I remembered that she consumed a lot of snow cones in the last few days that contain alot of the snow cone syrup juice such as blue-rasberry and cherry. Now I understand what's wrong. Thank you for calming my nerves.

    guess who's picture

    after downing two bottles of Boone's Farm alcohol, the blue kind, i had a nice surprise today..twice already, lol. wonder how long this is gonna take to go away? but now i kno nuthin is wrong with me. THANX:) !!!

    Mia's picture

    does pink lemonade do the same thing? even if i really didn't drink a lot? i had some seriously green poop earlier. also, i saw the comment at the top about people taking polaroid pictures, and thought, "wait would it not be better to take film pictures, and all around america (or the world, perhaps), photo labs will be perplexed and mystified by the sudden appearance of many green turds developing in their harsh chemicals. perhaps it could become a news topic! anyways, just a fun observation-speculation.

    Lindsay's picture

    I think Pink Lemonade does the same thing.

    NotOnMyEggsAndHam's picture

    I got my green from "Fierce Grape" Gatorade as well. Ingredients claim "Blue 1" and "Red 40".

    Isaac's picture

    every day i drink 2 liters or more of kool-aid since far back as i can remember and i have had green poop all the time. i just thought there was something wrong with me, until i stop drinken kool-aid for a week and it took a few days to go back to normal. then i relized it was the kool-aid.then i seen this site. now i know for sure its the kool-aid. green poop rules

    silvie's picture

    Another relieved Mum!My son will so pleased to find out the glorious green stuff he insisted on showing me was as a result of the blueberry crumble he ate the other day, although it didn't have the desired effect of getting him off school. Maybe i have found a way of getting him to eat more friut, as he is bound to want to experiment and show off the results!

    Laura's picture
    m 1+ points - Newb

    In my experience blueberries turned the stool black

    SethXv's picture

    Well, actually this works with jello as well you see I made 2 packets of jello (grape flavored) the previous night and ate about half of the jello this morning and behold the marvels! I had green poo being the keen and curious person I am I googled 'green poop' and came upon this wonderous website filled to the brim of brown goodness! After reading so much my eyes have turned brown! Thanks Brown stuff!

    Steph's picture

    My fiance has been having green poop consistantly lately and we began to worry. It turns out that after reading your report the common factor was "Boo Berry" cereal by General Mills, It has the Blue 1 and 2 dies in it. The mystery is solved! Thanks.

    cinderblock's picture

    God, the Internet is great! Your site was the first to return on a search for "bright green poop". Turns out it must have been a combination of the blue corn tortilla chips and this fruit dip that I made yesterday with red and blue dye. Whew! Thanks for saving me an embarassing trip to the Dr.

    coach2six's picture

    I'm just like many of the others. Thought something might be wrong with me, fo i spent hours checking medical sites and came across this one. Man am I relieved.... Guess it was ice cream cake with blue icing. I just think you've done a lot of us a GREAT service in relieving our worried minds.... Not to mention money we'd pay to doctors to have them stand there and scratch their heads, look a little puzzled and tell us to take two aspirins and call them tomorrow !! You are the BOMB....... Thanks..............

    Sal's picture

    Phew and Pew! My daughter drank a new blue vanilla milk drink this morning at a coffee shop and had the blue poop syndrome. We were perplexed until coming across your site. Thanks!!

    Jimena's picture

    Wow that was a scary situation!..i had like 8 glasses of purple kool aid yesterday ...i was freaked out this morning thinking i was dying...whew!!

    cc's picture

    just to let you know, some fruit rollups do the same thing , wheen eatin in large amounts 3-6 in a day, at liest it did to me lol.

    StarryBugg's picture

    LOL I am so glad I found this....

    I was paranoid... Didn't know why I was shitting ELECTRIC GREEN! Must be the Tropicana Twisted Grape Soda I've been chugging!! LOL

    OHMYGOD!!'s picture

    My 7 year old daughter went to the bathroom yesterday and her poo was neon green. I flipped out at first, but I realized that she had eaten blue cotton candy flavored ice cream and she loves to drink ice blue gatorade. I think the combination of both turned her poo green. Thanks to this website I have confirmed by suspicion and I don't need to call the doctor.

    Holly's picture

    Thanks guys...the culprit for mine would be the "blue icing on Wal-Mart cakes." I wasn't horribly afraid of impending doom, disease, death, and destruction...but I was a bit curious, so thanks for setting my mind at ease.

    nic's picture

    I just had one... i havent dranken coolaide or any sugary substance for a while..... and it was so dark green it made the toilet water neon green.... it was like looking into a drum of radioactive sludge with a floater ... definatly a kodak moment

    babs's picture

    After reading your site, my husbands green poop is probably due to eating blueberry muffins (dye enchanced blueberries) for 2 days in a row.

    Black licorice does the trick for me---emerald green!

    skeered mama's picture

    thanks to Laura I can feel okay. My poop was black and I was was the blueberry toping on the cake I had last night! WHEW, all better soon. Thanks!

    sharon's picture

    OH Babs! that must be what did it to me! black licorice. i landed here cuz i have had intermittent green poop at times, n i got curious what the hell! so i googled "green poop" n this was where i first landed. n then i was thinking; i haven't had kool-aid, nor any strongly colored thing! but then i remembered the black licorice i have been chowing on daily for a week! ah ha!!!! emerald green licorice poop :)

    Maine Dad's picture

    Thanks for the bright green poop article. Just like grateful Mom, my 2-year old daughter had some bright green poop multiple times in a 24 our period. I did a google search and this site came up first. For the sake of science, my daughter did not have purple Kool Aid but instead had a large amount of (my) black raspberry ice cream. I assume there is some blue dye in that purple ice cream.

    Bob's picture

    I hit the head this morning, and bright green was the color. I had three cans of grape soda the night before at the Fourth of July party. I figured I had some kind of cancer, until I came to your site. Thanks for the piece of mind.

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