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"

    Chip Lover's picture

    Thanks for the informative and entertaining website. I as well was scared of my green poop that has been lasting for 3 days now! I went online and was racking my brain what I ate to cause it. I had some foods that were green - but being a vegetarian I know that they usually do not cause this. I had purple sparkling grape juice last night. But not that much. Then I saw the post about the blue corn chips! That has to be it because I have been eating the things the last three days since my fiance bought me two large bags. They are my favorite so I can eat a lot of them and these are a new brand - that obviously uses a different dye that is affecting me. Thanks for easing my worries! Sounds like this is very common.

    jodi's picture

    well now i know and i can relax i thought for sure i had some kind of disorder or something...i guess consumming three cans of grape soda well do it good i love welchs grape soda and am addicted to it... i found it very interesting and can poop now with out worry...thanks

    MoonlitEden's picture corn chips. I was searching the net for what could have caused my unexplained green poop and I found the blurb from someone saying that blue corn chips would do it. Now I am not so freaked out.

    Greenie Pants's picture

    Well it looks like a few Gimlets too many will make your shit shine as well. The "Rose's" lime jucie concentrate has that pesty Blue #1 in it, go figure. Well hell I am relieved, in more ways than one. Happy Poop'n!

    Anonymous's picture

    Taffy, in varying shades of green, blue, and purple, will turn it green also, as I just found out.

    Mike Dean's picture

    I friend of mine recently poo'd and the results were white. I don't understand how this is possible. She doesn't understand how this is poosible either. If you could write my back and tell me what she could have ate for this to happen, it would be a great help. Thanks
    Mike D

    Diana's picture


    snort's picture

    I had frost (purple) gatorade and had neon green dump. I wondered why and u solved the mystery I love the internet and u guys.

    steve Cash's picture

    man i was takin a dump and i looked in the toilet and there was green sumptions of crap i was like whoa i wonder what made that green so i entered a search engine on what makes your poop green or somthin like that...and found this site after readin that weird turanisouras rex kool aid or whatever it was ..of some kool aid i never heard of...bull crap man...must bee a chinese product lol..but yea the first comment i read after that said somthin about purple kool aid and for the past 2 or 3 days ive consumed a large ammount of it and thats where i found of its where abouts lol...

    me's picture

    omg... i'm so glad i found this site! I was scared I had like, ass cancer or something when I starting crapping out forest green stuff... but reading these posts made me relieze that just yesterday I drank a very very blue drink, that must be the cause.

    professional pooper's picture

    I drank a bottle of red wine last night and I pooped a green/grey this morning. It wasn't spectacular but still notable. I can also relate to the Boo Berry cereal story. Glad to know I'm not the only one that likes to discuss defecation!! :)

    kay.'s picture

    i drank blue kool aid last night... and in fact i did have green poop.

    me's picture

    Thank God! I ate a HUGE slice of red velvet cake last night and this morning had BRIGHT RED poop! I freaked and almost called my mom! Glad to know it's just the food coloring. Great site! It saved me some embarrassment!

    Papa Pho Pho's picture

    I drank six quarts (so basically the 6.000 mL... over the course of two days and had this happen to me. The neon green, with greenish liquid coming off) I was relieved when a friend sent me this link since I have had gall bladder problems in the past that run in my family. A younger friend of mine is readying to conduct an experiment of his own on this topic... using this to get out of high school.

    Mike's picture
    m 1+ points - Newb

    ohhhh man, I think multi-grain chips can give a greenish-tint poop. The first time I pooped green I uhhh asked a co-worker (no easy thing to do) if they had ever pooped green. To my surprise, he said he had so I was extremely relieved and thought nothing more of it. Since then I've pooped green several times, including a recent one that spurred me to research it. What a site!

    joe from MA's picture

    COOL. My 3 year old son clipped off a bright green floater today. My wife was amazed and almost saved it. "If there was a sweater that color, I'd wear it" she said. She decided to flush. Worried my son had a defective terd dispatcher, I decided to search the net, and here I am. I asked what my son had yesterday at a birthday party he went to. "cake with a big blue baloon" My son is tickled that blue balloons make green poops. That's his new song. We now have a 3 year old blue balloon hunter on our hands. Youre right on about a green turd. It is neat. One time I did a big J poop. I called all my friends in. My brother did a white one with dark spots one night. The famous cow flop.
    THANKS FOR THE SITE!!!! blue frosting icing does make green poops.

    beamer's picture

    Thrilled to find your site!I have had this condition several time and have even asked a Dr. what this might be caused by to no avail.I figured it might be from somefood dye but was unsure until I narrowed it down to a raspberry ice cream that I ate in large quantities.Thanks for your site and insight.

    Hatcreek's picture

    After a few months of wondering why my poo has transformed into a green odysee, and a few minutes ago after an exceptionally green ''drop off'' I have finally made the connection. My green preen started right after I discovered I like Captian Crunch (Berry version). Now instead of worrying about what's growing inside of me, be it worms or fungi, I can confidently down 3 bowls here in a minute and just laugh the next time I take a dump. You can't tell me God doesn't have a sense of humor. He made us and our digestive systems, and the minerals on this planet for food dye for that matter...He created us to eat and poop, and occasionally poop green and laugh.

    mrb's picture

    -was wondering why I had such green poop, and after reading everyones entries, I realized it was because I've been chugging grape juice for the past few days. BUT it also reminded me that my sister once ate a tablet of easter egg coloring and it changed to the color of the tablet. Don't know if those are healthy to consume, but there's something for you daring folks to consider. Ttfn!

    the masterbeeter's picture

    One sunny morning I woke up and had discovered I shit my pants in the night. I was freaked out not because I shit my pants, but because my turd was completely bright red. To my dismay thinking it was blood I went to the emergency room at the hospital.The doctor just looked at me and shook his head.You've been stealing beets out of my garden haven't you? I'm calling the cops.

    anonymous of course!'s picture

    OK, so maybe the grossest part about this is that I ate an entire bag of sugar-free black licorice (it didn't even taste good), but my poop was a fascinating shade of blue for about 2-3 days. Amazing.

    Michelle's picture

    You have finally solved my problem! Well, not really a problem, but a major curiousity. My poop has been neon green for a while now. I mean seriously neon. I have been wondering if it would light up if I took a black light to it. I'm still thinking about performing the experiment. Anyway, now I know it's from all of the Kool-Aid that I drink. It's cheaper to buy than other liquids, so I've been drinking that only. The mystery has been solved!

    Len's picture

    Well, now I know! Because of a cold, I've been drinking lots of Twister and yesterday's feature flavor was "blue" something. This was the second time in a week and I thought I best hit the net for some research. About a year ago I experienced the same thing after eating about a half pound of Twizzlers black licorice. Do you think it could have something to do with the name?!
    Also, it's comforting to know that I'm not alone in checking the results of my labors.

    JHoney's picture

    I am pretty sure the reason for my beautiful, wonderfully shiny, deep christmas green poop is because of drinking jagged ice purple-colored powerade with blue 1 dye in it. I only drank 2 bottles of it in a day but that seems to be the cause.

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

    I will add another count for Fierce Grape Mountain Dew turning shit green. I drank some a few weeks ago just to see if it would happen. Ta-da! Green!

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

    kimmie's picture

    I just went to the bathroom, and upon finding i pooped a disturbing color i came on here to research, my boyfriend was disturbed.

    Last night I drank about 6-8 cans of grape soda. So I now see what happened. I hadn't eaten much yesterday but one meal, and grape soda. What a trip.

    Not as cool as when I was in college and hadn't eaten anything in 2 days and ate chinese food with the pork in the neon red sauce. OH MAN NEON RED POOP. try that out sometime.

    Brandon's picture
    m 1+ points - Newb

    I have recently consumed mass quantities of oops all berries cereal by captain crunch (1/2 of the big value box). With plenty of milk (1/2 gallon) It produced a moderatly green poo but not super green. I decided to try to find out what the cause of it and stubled on your site. I believe I metabolized the dyes which produce this effect. Unfortunatly the evidence was flushed before i found this site. Otherwise I might have taken a picture of it for the records. Anyway! plesant pooping!

    Lynn's picture

    I just pooped bright green and freaked out! I thought maybe it had to do with the 4 bags of Ferara Pan Jaw Busters that I've eaten in the past 3 days. They are red, green, yellow, orange and purple. I wasn't sure it that was it or if I had some weird disease. Thank you! Now I know that it WAS the Jaw Busters!

    Rachelle Repp's picture

    That is kinda interesting but also gross!!!!!!!!!

    joppie slows's picture

    Once I was at school and it was halloeeen and the bathrooms were all full and I had drank kool aid and that makes me have poop. and I pooped my pants and it came through my pants and fell to the floor.

    beth's picture

    black cake icing also turns poop bright green!

    robert's picture

    my poop has been green for a length of time. is that bad or good?

    thomas's picture

    Gogurt, even in small quantities, turns a toddler's poop bright green. Contains Blue #1. They should put a big sign on the box or something:

    stace's picture

    To funny I drank a ton of tropical punch kool aide and grape kool aide last night. Now I can go to bed without worrying! Had me scared for a bit though!

    Talyor'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...

    Poop-head's picture

    I justed pooped, it was a little red and a little neon green. Hey did you poop when you were depressed.

    Sharon's picture

    I purchased cupcakes from Sam's Club. All different colors. My son consumed a green one and had bright green poop this morning. I was concerned and called Dawn Foods the maker of the icing. I feel somewhat better after reading this site. No word back from Dawn Foods. Thanks! No more food coloring cupcakes for my son or classmates.

    Michelle Mendenhall's picture

    Hi-C Tyhoon Berry Blue fruit punch will turn your poop green too. Pepto Bismol will turn it black. We really are what we eat!

    Dan Grindle's picture

    blue gatoraid mix will also turn your poop a brilliant bright green. I've had a couple green poo's in the past but after a drinking a liter of blue gatoraid my poo was so green it alarmed me enough to search for the cause. Thanks for solving one of the biggerst mysteries in this modern world.

    Schven's picture

    Anyone ever pinched a blood red loaf? Years back my fiance now wife went on a weekend trip with another couple.

    My buddy and I while shooting and drinking large amounts of beer ate heaps of red pistachios. Sunday evening after coming home I had to go. I screamed in terror after wiping. Hell I thought I was bleeding. I look into the pot and see large blood red deamons. My better half then said "Hey its probably the pistachios" Why didnt I think of this? Must have been the beer.

    Katie's picture

    What a relief! I have been telling my boyfriend (to his dismay) all about my BRIGHT green poop for the past couple of days. I couldn't figure it out...what had I eaten out of the ordinary? Could stress cause this? Cancer? So of course he didn't believe me, nor would he come look so I had to worry all on my lonesome. Well, after a late night poop, I decided I needed to figure this out. This was the first website I went to after searching and lo and behold...I just recently became a sugar-free grape koolaid consumer! I am OBSESSED. Drank 4 big cups tonight. (It has replaced my diet coke addiction.) Well, green poop or not, the koolaid is here to stay--but thanks for the info!

    Green skids's picture

    :D what a great site, first result for at Google search on green poo. For the last 2 days I have wondered and worried about my own green meanies until reading this.

    I picked the orange and blue M&M's from 4 large packets, (to take a photo) Then I ate them seperately. So about 1 large bag of just blue M&M's 2 nights ago. Anyway, thanks for putting this site together :D

    G-Moneey's picture

    Yo, thanX for the input. It was worth my wild to read what ever one had said. ThanX

    GReen poo person's picture

    hey i was wondering does bud make your poo a weriod green color too becuase i just shitted and it was pastle green and it didn't look good but i have smoked bud a lot in the past month please e-mail me back explain this

    Sal's picture

    Helpful information. Thanks everyone!!!!

    anna's picture

    good to know i'm not the only lucky charms eater who got green poo. haha, i guess from now on i'll stick to the cereals my mom used to let me get (honey nut cheerios, honey bunches of oats, the reals stuff...)

    greencrapinbum's picture

    i have green poop and i haven't eatin any green stuff or drinkin anything does pepsi or colored animal crackerz give green stool cuz i have it really bad for like two days and a stomache ache

    Julia's picture

    I ended up on this site after a Google search... I had already figured that it was something I ate that was causing my bright green poop. However I was wrong about which color was causing it. Now I know. Moe's Southwest Grill "blue corn" tortilla chips are NOT blue corn. They are dyed and I ate a ton of them this past weekend. How's that for finding out a product is bogus?! LOL.

    mommy's picture

    My son ate "berry Fruit Roll-ups and some fruit chews, yep bright green pooh.

    green's picture

    well for thelast 2 days i've been poopin green crap and i didnt kno wut i ate but when i was reading some people said those green marshmellows from lucky charms ceral made there pop green and i ate almost a whole bag of them so i think that is the reason

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