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"

    Dave's picture
    PoopReport of the Year AwardComment Content Moderatora 10000+ points - Super Pooper

    I encourage all PoopReports to drink copious amounts of Kool-Aid this Fourth of July weekend, and report back your results. We should attempt to mimic Dave J's experiment as closely as possible... so try for at least 3000 ml (that's roughly 3/4th of a gallon) of Kool-Aid along with a similar amount of water, or, if you're a real trooper, 6000 ml (1.5 gallons).

    Even if you don't stick quite to the way Dave J prescribed it, please report back on your findings.

    Brown Seymour's picture

    Wouldn't it be easier to just eat packets of the powder? Or make a sludge using a small amount of water, so as to chug 10 packets at once? I think that would be the most expedient route to some seriously green poop.

    Oh, if folks could snap a polaroid of their bright green poop and post it, that would just be super.

    Dave's picture
    PoopReport of the Year AwardComment Content Moderatora 10000+ points - Super Pooper

    Brown -- you may have a point with the powder. In the name of scientific inquiry, I suggest you try it.

    Dave J's picture
    l 100+ pointsm 1+ points - Newb

    Brown- I'd toyed with that idea...however, I wasn't sure how the dyes would be metabolized in the absence of sufficient water (i.e. the way I first consumed it). If it takes a lot of water for the enzymes in question to do their "doody", the results of your hypothesis might be disheartening. Who knows tho? Since I'm in the real world now, and don't have immediate access to 24 dim-witted willing college drogs, I'm at a bit of an impass in my research. I'll provide consultation with anyone who wants to pursue it tho!

    Turd Burglar's picture
    m 1+ points - Newb

    now this is what "science" is all about!!!

    Mike's picture
    m 1+ points - Newb

    Hey Dave J, this was a Kool experiment. It's interesting that it was real easy to get volunteers. How did you stop a dude from taking a dump mid-experiment? Also, how did you supervise these dudes when they took a dump? Did they shit in the toilet or did they shit into containers so that you could collect your specimens?

    poopster's picture

    my poop is green anyways

    Darth Bauls's picture

    I am constipated. I havent taken a healthy poop in over a year. I do not drink enough water.

    Ball Lickers

    Justus Loonz's picture

    I like both of Brown's ideas. Eat the powder and consume a minimum amount of water. Then take a pic of the freshly spawn grogan for the masses. If I do this in the next week or two, I'll go to UseNet and post the pics in then take plenty of antacids. The subject line I will use is "green green grogans of home." and hopefully the digicam will do it justice.

    Dave J's picture
    l 100+ pointsm 1+ points - Newb

    Mike- Good comments. It wasn't hard to get volunteers; after all, it's an all-guys floor...if you were a shameful shitter, you'd probably die. I delegated supervisory roles to my roommate and my neighbor. They didn't actually "witness the birth", but they made sure there wasn't anything funky going on (auxillary food dye, etc). The collection was handled by swabbing a long q-tip into the loaf, the tip of which was then placed into a microfuge tube, and the handle snapped off. That was done by the poop creator. It wasn't hard to prevent mid-experiment dumps; I just asked them not to, but if they absolutly had to, then they had to write down the time of the dump. The purging took place about an hour after the experiment ended; since the dye is soluable in water, it didn't have to pass all the way through the colon; most of it was absorbed in the ascending colon, and sent directly to the liver and kidneys.

    Hope that helped!

    notachance's picture

    my wife had a childhood memory of her favorite cereal, Boo Berry which i am sure many of you all remember. she seemed obsessed with this cereal and wanted to find it and eat it again, this proved to be difficult due to the limited market of Boo Berry , it seems that you can only find in select stores nation wide because most stores wont stock it for some unknown reason. well i found that it could be purchased online and shipped to your door so i ordered 4 boxes...the smallest amount you can order. it arrived and i must admit it is very very tasty. well we ate all 4 boxes in a matter of 2 days, this was a mistake! after about 3 days i had my first in a series of about 8 glowing green shits that smelled absolutly HORRIBLE!! our one bedroom one bath apartment was borderline unliveable for almost 3 days.

    just thought that this might help warn any unsuspecting people out there about the ghost shits also could prompt a new study??

    KMM's picture

    Hey anyone can change thier poo colors ;) I make ramen noodles with food dye in it and eat that stuff all the time I get loads of different colors =] just letting you know =-P

    Sputtering Dudly's picture

    Other colors that I know how to make are...

    Orange, make sludge with Generic Tang then drink way to much

    Purple/Blue Some slushpuppie flavors with extreme sauce added have had amazing effects on people I know

    Geronimo!!'s picture

    In one of my biochem/nutrition classes my prof mentioned a dye used for fecal energy testing - I can't remember what it's called but it had the same effect - BRIGHT GREEN - if you're a bchem guy, what was it called? It's banned now for use in humans (thank god, my prof used it on himself and he's got issues) but it is still used in ruminant testing - any ideas?

    Dave (the author)'s picture

    Geronimo- It could be methyl blue- that stuff is also used extensively in urinalysis, but since it comes out in your pee, I'm not positive it'll retain in the colon. Another option might be bromothymol blue, but I'm pretty sure it's always been known to be toxic...might be wrong!

    THOMAS PRITTIE's picture



    I cant believe i am contributing's picture

    I have found that Red Velvet cake mix will cause a quite brilliant neon red poop. I was quite surprised the evening after I consumed 2 peices of this cake. The dye is incredibly strong and took me several cycles before it went back to normal color.

    Jolene's picture

    I just went poop and when i wiped i realized that my poop was green. I couldn't understand why since i couldn't recall eating anything that would do that so i got a little nervous and decided to get online and see if i could find any possible explination. I came across your site and realized that the strawbeerry kool-aid i have been drinking was more than likely the culprit. so thanks to your experiment i know that the only thing wrong with me is the beverage i have been consuming.

    anon's picture

    Ditto last comment. Found that it was green. Went online. What I had was a couple of packs of grape bubble gum in 3 days. It was bubbilicious. Apparently they use blue food coloring.

    Clyde's picture
    m 1+ points - Newb

    I, too, have used Kool Aid to turn my poop colors. I go now to type my story - I will call it "Me and Darin and the Blue Poop" and I will submit it to this site for posting. Perhaps it will be funny.

    The poop monster's picture


    ps's picture

    What a website! I thought I was the only one contemplating poop colors and pooping's affect on health! Great job! I'll be checking in again. btw,as serious as this topic is, I'm falling out my chair, laughing...think I might poop!

    Tsam's picture

    If you want green poop, go to a sonic drive in and drink a 44oz blue coconut slush. You'll be shitting green for 2 days...

    Mike Hunt's picture

    2liters of Faygo Blue Moon Mist = Green Shit

    Julie's picture

    I ate Extreme Berry Sherbert from Baskin Robins last night, and today, almost fell into the toilet after I wiped, and noticed a bright green line on the toilet paper. I got up to investigate further, and oh my god, it looked like I'd shit out little clumps of grass clippings.... pure green. Of course curiosity (and wondering if I was dying) got the better of me, and I logged onto yahoo and typed in "green poop" and thankfully this page pops up.... Now I don't feel like such a weirdo after reading all the above posts!!

    Dana Rosen's picture

    You guys should try the "Ocean Water" fountain drink from Sonic Drive-In. It is a mixture of Sprite, Blue Coconut flavored syrup and crushed ice. The result is neon green. NEON GREEN! Nothing like looking in the toilet at 3 AM and seeing neon green stool. As Julie had explained in her post - "wondering if I was drying" I consulted a nurse friend and was reassured it was all cool and a result of the food coloring used in the Blue Coconut syrup. Oy Vey! Once the initial shock of neon waste wears off it becomes pretty cool.

    Amy's picture

    I have experienced the green poo! The only thing I can think of that caused it is the mango sorbet I have been eating these past few days. It is only thing I've eaten with food coloring in it, so, evidently the green poo can come from many different colored sources.

    Gordon's picture

    My doctor has confirmed in the past that my iron supplements when not digesting properly were the cause of my greep poop. Switching form a tablet to liquid form resolved this issue for me. Again - obviously green poop can come from many sources!

    The Bunger Sisters's picture

    I noticed the same phenomenon--neon-green shit--when I drank tons and tons of Grape Kool-Aid. None of the other flavors had any effect on my bung hue, just the blue dye in the grape-flavored variety.

    Had a friend, a female, who drank tons of "Hot Damn" (cinnamon schnapps) at a frat party one night, came home at the end of the night, and shat bright red. She thought at first it was blood, and that in her drunken stupor, was inadvertently butt-plowed by a gang of frat boys. Even went to the hospital. Turned out it was the red dye in the liquor. True story!

    Big Boo's picture

    You didn't have to drink that massive quantity of Kool-Aid. You could have done like I did and eaten one of those extra big sugar cookies that had been decorated with blue, green and white frosting to make it look like a picture of the earth. A day after ingesting that little treat I was both shocked and fascinated to find that a neon glowing green shit in the toilet. I should have taken a picture.

    Beaux's picture

    Purple or blue liquids are not the only thing that will make your poop green. My fiance and I "discovered" that eating blue corn chips will result in kelly green stool. And a friend of ours ate an entire box of Boo Berry poop.

    The Soup Nazi's picture

    I've found that the Berry Luzianne Smoothies have produced green stools as well. I'm glad I ran across your site. Now if I can come up with some purple soup!

    Captain Asparagus's picture

    I've had my share of run-ins with green poo as well. One time that stands out in my mind occured some time in the early eighties after having consumed two or three bowls of "Smurf-Berry Crunch" cereal, which contained tiny balls of red and blue. Ever since then I have been on a mission to find a way that I can make a green fart cloud. If you have any suggestions I would appreciate them. Thanks.


    Juls's picture

    All I have to say is: "Fruit Rings" (Finast brand)

    Thanks to your website for saving me a trip to the doctor! :)

    lauren's picture

    thank you so much for telling me why my fiance's poop has been green. He loved to drink koolaid all the time. He thought he had prostate cancer until we came to your website and new that nothing was wrong with him except for drinking excess amounts of koolaid. Thanks my pooper scooper!!!!


    P-Dub's picture

    Two more stool hue shifting delights. Blue cotton candy got me a couple of years ago, and my latest was with blue cake frosting. I ate so much cake frosting I got liguidy poo and changed the water green. When I wiped it looked like a grass stain on the toilet paper. Sheesh this site set my mind at I'm goona have some fun with it.

    S Ayres's picture

    My 6-year-old son picked the ice cream for my birthday celebration: Blue's Clues

    blue artificially colored vanilla ice cream.  We both have had a bowl in the afternoon for the past

    week and in case you didn't know, poop is a popular topic for 6-year-old boys. 

    We have been laughing at our crap all week.

    But alas... our week-long green poopfest is coming to an end. We finished the last of the Blue's Clues ice cream yesterday

    so today will be the last "greenie".

    I'll not get another 'till St. Paddy's Day.

    ray-ray's picture

    i have been drinking this cranberry/grape juice for the past few weeks and i have been having green poop! i thought i was going to die. but now i know other wise. you guys rock!!!


    Joey's picture
    m 1+ points - Newb

    the new hershys green/chocolet syrup will do it.I drank one glass of it last night and had a big green poop today.

    firechild's picture

    I saw a lovely neon green glow in the toilet bowel for the first time in my life today. It was totally freaking me out b/c i couldnt think of ANYTHING i ate or drank that was green. (including any type of pill, candy, or vitamins) By looking on this site, it MUST have been the "jagged edge" powerade i drank. It was a very deep purple, and it seems like grape/purple is the key to green stool =). It was easy to track down because i hadn't been eating or drinking much at all recently. Thanks for this site for saving me alot of worrying!

    Dave J.'s picture

    I just popped back into my old stories for a momment, and I just want to thank all who wrote about this article; I'm glad I was able to help, albeit in a "behind" the scenes way...


    Dave J.

    James Neaten's picture

    I ate some of this ice cream at TCBY called African doo rag, it was like a blue rainbow color, I shat blue instead of green, it looked like playdough and I wanted to put it on a bun and eat it like a hotdog on the fourth of july. But of course I just admired the little fella and sent him to doo heaven.

    P-hole's picture

    The first time i went to the restroom today i saw that my poop was green. i was kind of weirded out by the whole sittuation so i wanted to know the cause. i haven't eaten any purple cool-aid today (although it sounds real good.) but as i read this i looked back and all i have eaten today was lucky charms, cheese sticks and a bacon egg and cheese pocket. I will now test it and see what is making it so green. Thanx Dave J.

    big mike's picture

    i'm siding with firechild on this one. i just blew a neon green one out- kinda scared me, hit the search engines, and BAM- i found my answer on this page. Damn Jagged Ice powerade

    Tommy's picture

    Have your tried "Roberts grape drink?". It also produces a bright green shit! :)

    AP's picture

    All I ate today was a Canadian Pizza, Ceasar Salad and Garlic Bread from Pizza hut, and I almost fell over when I whipped green stuff off my butt. Why is it that we look at the toilet paper anyways?

    Neth McBain's picture

    You'll be happy to know that your copious research has eased another mind. I too noticed two green turds today and started searching the web for an answer. Turns out that I had two grape sodas (which I never drink) at my sister's house yesterday which surely contained the dreaded blue dye. I'll have to find out for sure and follow up.

    Green Pooper's picture

    I just had green poop! But I didn't drink Kool-Aid or anything blue/red. I thinkk it has to do with my intolerance to lactose. I've had a lot of those lactose-enzyme pills today. Mine wasn't lime green, it was more of a steamed spinach color. =)

    Dani's picture

    I had green (veggie green) poop today, and was a little worried. Because of this webpage, I figured out that it was the quart of Crystal Light Raspberry Tea that I drank last night. Thanks!

    kadath's picture

    Phew! That's a load of my mind! When I first entered the Army, the next day my poop was bright green. It gave credence in my view that they put stuff in that reception center chow. Good to know now that it was only probably a side effect of americana crap.

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