Why is my poop green?

As a science blogger, I hear a lot of interesting questions, and this is one of the more interesting questions I’ve heard in a while. It is, I’m sure, rather disconcerting to notice that your feces are the color of a corroded penny, and not know why. Or, if your feces are the usual brown color that our species tends to produce, perhaps you’d like to know how to make your poop green for Saint Patrick’s day. Either way, read on:

So, why is my poop green?

Does green poop mean cancer? Liver disease? That you are an alien? Or was it just too much partying on Saint Patrick’s Day or something you ate?

There are several reasons why one can have green poop, one or two of which should concern you. Naturally, one of the possible reasons you will encounter on the Internet is cancer, but that is highly unlikely. More likely it is something else.

If you are on antibiotics, that could be the reason. Antibiotics can cause greenish diarrhea. Also, various factors (including antibiotic use) can cause bacteria that are not normally active in your gut to become more active, producing a green stool. Although most food that you eat, no matter what it looks like, ends up being brown when it has been converted to poop, some natural foods will retain their green color. Also, in the early development of your stools, they are greenish. If something causes feces to transit the intestines more quickly than usual, that could cause a greenish effect.

Quite possibly the most dramatically green stool is caused by food dyes. If you have a green stool, ask yourself if you’ve eaten anything with green food dye in it lately. If you have not, recall that green is a combination of yellow and blue. Copper green poop can be generated by the regular consumption, over a few days, of Metamucil and blue Gatorade. Don’t ask me how I know that. Anyway, consider the possibility that you’ve somehow combined something yellow and something blue to produce green. Try the orange Gatorade for a while.

If you have a green stool, wait a few days and keep checking, and consider the food dye explanation. If that does not satisfy you check out the Mayo Clinic web site and consider seeing your doctor. If you don’t have green poop but would like to, for Saint Patrick’s day, try the Metamucil and Gatorade idea, but only after consulting your doctor, who I’m sure will be very interested.

Finally, I hope you do realize that you are seeking potentially important medical advice on the blogosphere. I’m not sure that is such a great idea. (Though I do like the Mayo Clinic site.)


See: Poop: A Natural History

Other posts of interest:

Also of interest: In Search of Sungudogo: A novel of adventure and mystery, which is also an alternative history of the Skeptics Movement.

Photo Credit: jurvetson via Compfight cc


  1. #1 peter
    February 20, 2011

    Try to eat a lot of pickled beets. I sometimes get the urge and make a meal out of them. Red stool can be even more disconcerting.

    Green poop is easily achieved by eating the first freshly harvested stinging nettle meal in spring – I mean a large meal. Just prepare the nettles like italian spinach, and wait to the next day. Nice green poop.

  2. #2 Ken... Just Ken
    February 20, 2011

    My Girlfriend and I each had a some very disconcerting days a few years ago when we each had incredibly green poop. It would last a day or so and then go back to normal. and then a few weeks would go by and it would happen again.

    Until we compared notes on this problem and realized we had the problem at the same time and discovered it was always the day after we had ice cream we’d used “Incredible Hulk Chocolate Syrup” on.

    The food coloring was so intense that it covered the brown of the chocolate, and continued to keep it’s color … er… afterwards.

    I was proud of us for figuring out the problem, she was just grossed out.

  3. #3 Crystal D.
    February 20, 2011

    Actually, I’ve had green happen from red food dyes. Not sure why, but absolutely the reason, as my mother and sister also had it happen after a red slushie drink from BK once… lol There is also a purple sorbet/slushie push pop I eat that makes green somehow as well.

  4. #4 Jake
    February 20, 2011

    I once had alarmingly green poop the day after eating an entire package of blue-raspberry licorice. I enjoyed finally finding out just how long it takes my food to transit the digestive system.

  5. #5 Iron Maiden
    February 20, 2011

    Iron supplements may also turn your poop green.

  6. #6 Art
    February 20, 2011

    Gorging on Fruit-Loops tends to turn the poop green a lovely shade of deep green. I understand it has to do with the food coloring. Gorging on vanilla ice cream tends to whiten it. Normal food consumption with the ice cream goes toward tan. Combine Fruit-Loop with the ice cream and you get a nice bright shade of green. Don’t ask how I know this.

  7. #7 Richard Simons
    February 20, 2011

    It happened to our dog when we left it alone for an evening and it ate an entire, newly planted hibiscus bush!

  8. #8 Vince Whirlwind
    February 20, 2011

    Red wine makes mine green, if I drink too much of it.

    I concur with the poster above who mentioned the eating of beetroot can have very disconcerting effects. I like dried shredded beetrot, and it only takes a few mouthfuls of that to create a subsequent “Oh my god I’m bleeding” moment….

  9. #9 Adela
    February 20, 2011

    If you are extra eager on the high beta carotene veggies like pumpkin you get a very 70’s decor shade of orange.

  10. #10 Karen
    February 20, 2011

    Eating crayons also changes the colour of poop. What?! Not me, it was my dog who ate the crayons. Sheesh.

  11. #11 Lorne
    February 20, 2011

    I’ve also gotten green poop from eating a big bag of BBQ flavoured peanuts. Now I’m not sure if it was the red food colour or the peanuts.

  12. #12 tuibguy
    February 20, 2011

    On a semi-related note: Why does pee color vary? Is it based on diet?

  13. #13 Adela
    February 20, 2011

    Yep diet can change that colour. Excess VitB2 gives you bright day glow yellow. Some diseases change the colour as well.

  14. #14 Azkyroth
    February 21, 2011

    Eating an entire pomegranate a day for a few days in a row produces a dark blackish-green.

  15. #15 Rob
    February 21, 2011

    there’s something else at work here too. So the color brown can be created by combining the colors red and green. it just so happens that during normal heme catabolism (the breakdown of old red blood cells), you get two primary bile breakdown products, bilirubin and biliverdin. As their names suggest, bilirubin has a reddish tint, biliverdin, a greenish one. The combination of the two acts to color fecal matter. If there is an inbalance one way or the other, poop changes color.
    Pedialyte can also REALLY affect the coloration btw.

  16. #16 abb3w
    February 21, 2011

    Add black jellybeans to the list of food sources that give a green result.

  17. #17 Wallace Turner
    February 21, 2011

    I spent last Thursday morning disinfecting a customer’s PC. He got infected by a virus whilst checking up on a medical condition on the inter-webs.

    He didn’t appreciate the irony.

  18. #18 DuWayne
    February 21, 2011

    My three year old has finally become keen on pooping on the potty, because he can actually see it after. He was especially excited by the mix of brown and green that came out the day after he had Jelly Bellies for bassert last week. He was especially enthusiastic with his potty dance after that one.

    Now if only he would go to sleep already. We escaped our power outage in a Grand Rapids Holiday Inn and both the boys are having sleep issues.

    peter –

    Yeah, I had a complete freakout after eating a dessert a friend made. She’s a fucking hippie and as such used evaporated beet juice as a sweetener.

    (Ahh, the pleasant, albeit disconcertingly loud snoring of the Dave. Caleb (the nine year old) seems to have evened out his breathing too. About bloody time.)

    I don’t know exactly what else was in that – it may actually have been something in my cilantro pasta sauce, but the beet combined with something else we ate, produced a deep, viscous red that emanated from the stool. It wasn’t until another friend who ate with us that night called, freaking out about the same thing, that I realized it was probably something we had eaten. That was not the best way to start the day though. I wasn’t through my first cup of coffee and first cigarette of the day, before I was convinced I had another perforated ulcer. I very nearly went to the ER, but was thankfully slowed down by my preparatory bong toking (there was no way in hell I was going into that ER without the cushion of being seriously stoned – I have been through an actual perforated ulcer and believe me, getting stoned first helps*). By the time I was gathering up the motivation to seriously consider getting on the bus and heading to the ER, I had talked with first one freaked out friend and then had a roommate (kind of, I was actually more of that hippie you let sleep on the couch who never leaves**) confirm that she had also experienced the disconcerting bowl movement of doom.

    tuibguy –

    As mentioned, certain B vitamins can turn it neon yellow (when combined with a shitton of vitamin C it starts to get opaque – which can lead one to stare for quite a while after having ingested a certain lysergic acid). Various fungi, especially shiitake mushrooms, will turn it brownish – as can Welbutrin – both fungi and welbutrin can produce a host of odd smells in urine. Beets can produce a redish tint – though thankfully purplish enough to prevent it from appearing to be blood. Kale can produce a slightly greenish tint and very bitter, slightly musty smell. Spirulina and blue-green algae produce a blue-green tint and nutty-musty smell.

    There are really quite a few things that can affect urine colour and smell.

    Azkyroth –

    That actually explains something I wondered about when I was on a huge juicing bent (I still love juicing, but this was an obsession – back when I actually lived with the aforementioned vegan fucking hippie chick). I became particularly fond of juicing pomegranate, onion, ginger (she has a Champion juicer), cabbage and carrots together (Ok, I’m a fucking hippie too – plese don’t tell anyone). It actually tastes quite interesting (in a good way), but I was having really dark and funky smelling stools. Given that I was mostly eating vegan (with the occasional steak or hamburger on nights I didn’t mind not having sex), things should have been rather lighter in color. She tried to get me to do a “cleansing routine,” but I had my limits – twelve grams of psyllium husks, as well as a herbal blend “known” to help stimulate healthsome, “healing” movements*** was definitely one of them.

    I suspect that tart cherry/blueberry/grape juice also causes this phenom. Least ways, that would rather more comfortably explain a rash of that a couple weeks ago.

    * This was several years ago, when I was still smoking pot – a lot of pot. I have since gotten a firm handle on my substance abuse issues, of which daily (hourly?) pot smoking was one manifestation.

    ** At least until you change the locks, start actually locking the door, pretend you moved, or actually move out.

    *** It only cost $78 for a two week journey into colonic bliss. Knowing what was in the herbal blend, I could have reproduced it rather closely with five plants I could find in the woods and three others that cost abt $6 between them, for about five times what would be needed. Just two of the ones that are easily wildcrafted (Ie. found in the woods – or marsh) would have and on occasions when things have been a bit stopped up have for me, worked things out as it were.

  19. #19 Kitchen Stools
    March 4, 2011

    Hi, Thanks so much for visiting and also for the kind words. I will definitely stop by your blog. I’ll look forward to seeing you again soon.

  20. #20 Lauren
    May 22, 2011

    My poop was green today(Sunday) and yesterday morning. The only thing I can think of as a reason was I ate a hedge rose made of icing from a cake firday night. Could that be why?

  21. #21 john
    July 23, 2011

    Why is my toilet seat green?

  22. #22 Scott
    September 23, 2011

    Funny, I posed this “why is my poo poo green?” question today after taking 3 incredibly huge dumps in 12 hours, the last 2 of which were chlorophyl green. Then, after viewing some answers I figured the 8 Little Debbie Swiss Rolls I gorged on before bed had probably done the trick.

  23. #23 munni
    September 27, 2011

    muznah humayun
    rameen humayun
    izza taimur
    yasmeen humayun
    naheed aslam
    ch humayun
    mahad rameen
    kionta shena druknima muuto wa mughu de kano . amen

  24. #24 Nora
    October 7, 2011

    Green stools are not a big deal (as a rule) and not a reason to worry. Red and discolored stools are a warning sign. The former may point to blood in your stools (that’s a bad symptom – ulcers, cancer or intestine damage). The latter may occur if you are taking certain medications, like simvastatin. In any case, you need to contact your doctor.

  25. #25 Jazzy
    November 21, 2011

    I had green poop today and I was like WTF is wrong with me.Then,I came here and noticed I wasn’t the only one that has green poop. I feel much better now. I thing it was from the salad I had yesterday night. Thanks Everyone

    Jazzy Brown

  26. #26 I know why
    January 13, 2012

    Welch’s Grape Soda. Drink three cans the day before St. Patricks…

  27. #27 Miranda Green
    January 29, 2012

    I started to study the issue of green poop after running into it (oops) one day myself. And I can tell you, very often it’s the dyes used in foods and drinks, like dark blue dyes or Kool-Aid, or grape juice. I would not recommend such tricks. Stop eating these foods and green poop will be gone in a couple of days.

  28. #28 kelly
    February 9, 2012

    I have been having green poop for the last three days, and it’s freaking me out! What can I do to make it go away?

  29. #29 Greenanator
    April 11, 2012

    I have at least three handfuls of frozen blueberries every morning in a smoothie… I’ve been backed up since yesterday. I guess this explains why I just took the most massive green poo imaginable.

    Who knew blueberries could turn your crap dark greenish?

  30. #30 pukingfrosty
    April 28, 2012

    Blueberries consumed to excess can also cause bright blue poop. My diet of green curry and kale on a daily basis had vivid green results when mixed with blue raspberry fruit twist as well.

  31. #31 olita
    north carolina
    May 18, 2013

    My stool has been green for a couple of days. should i be alarmed. Also i have been detoxin my body frm alcohol. cud that be the cause????

  32. #32 supergirl
    June 29, 2013

    I ate a whole bag of black licorice last night but I also started to take Black Cohosh for becoming a cougar. This morning, my poop was green and at first I thought, “oh that must be the cleansing benefits of the black cohosh”. Funny, IRONIC, it’s the Twizzlers I ate last night to official kick off the Canada Day long weekend.

  33. #33 TheGoldenGirl
    NW Indiana
    October 2, 2013

    I’m so happy that I’m not the only one this happens to! I actually thought it might have something to do with my Crohn’s disease, but the food dyes make sense. It only occurs with me when I have anything grape or purple colored

  34. #34 southern773
    san Diego
    October 25, 2013

    i baked some Halloween cupcakes dying the bread and frosting black.. Today my poop was green; go figures!

  35. #35 Nick Theodorakis
    October 26, 2013

    FD&C Blue 1, a synthetic food dye commonly used in the US, is rather notorious for this. Note also black dye (e.g., use to make Halloween-themed cupcakes) is just a high concentration of Blue 1.

  36. #36 Frank
    October 30, 2013

    I had Frankenberry cereal with fresh blueberries, a smoothie and red velvet cake yesterday…the next day my poop was lime green.

    I think the most alarming poop was a bright red one that was accompanied by horrible ring of fire. It was probably from the food due but man…it burned and was such a vivid color.

  37. #37 Justin Bieberlake
    Lizardpiss Arizona
    October 31, 2013

    Happy Halloween. I ate cupcakes with orange frosting. Green poop. Yea!

  38. #38 Buddy
    February 24, 2014

    Everytime I drink grape gatorade my stool turns blueish/green

  39. #39 Meagan
    September 9, 2014

    So I came on this site to see why I have super green poop, usually I know because of what I have eating and I just couldn’t figure it out and then I remembered that I ate like 3 bowls of Captain Crunch (all berry’s) cereal which is very color full lol so I know why now

  40. #40 JODI
    January 1, 2015

    WOW having an online discussion about the color of everyone’s bowel movements, DISGUSTING AND I WORK IN OPERATING ROOM. YOU PEOPLE MUST ALL BE REALLY BOARD!!!! I can see to Google up something before you seek medical attention, but to have discussions about fecal matter. WOW what has this world come too. That’s private, personal information. If you need someone to talk to yous about your problems then go to the doctor. OMG! no life. I never thought that there would be a blog page to talk about everyone’s poop. YUCK SICK F>>>>>> PEOPLE.

  41. #41 Julia Griffith
    February 14, 2015

    JODI, get over it. There’s no reason to run to the doctor every time to get answers; especially if there are no other symptoms. I’m a nurse and talking about feces is no big deal. You work in a hospital and this bothers you; Really???

  42. #42 Greg Laden
    February 14, 2015

    No, we’re definitely boards.

  43. #43 Sofia Yusuf
    February 20, 2015

    My daughter has the same problems and we worked out she had been eating jellybeans lol

  44. #44 Lynn
    United States
    March 29, 2015

    Jodi needs to get over herself. I’m so glad I found this page. My doctor just started me on very high doses of Vitamin D for the next two weeks. The last three days my stools have been very bright pea green. I was convinced that it had to be the Vitamin D turning my stools green. I googled if Vitamin D could turn stools green and found this page. After reading all of the comments, especially the one about Little Debbie Swiss Rolls and the one about FD&C Blue 1 food dye doing the same thing, now I know it was the box of Little Debbie’s that I ate over the last week that has done it. I avoided another expensive and somewhat embarrassing trip to the doctor to ask why my stool had turned green. I’d much rather find out the answer for myself when it is possible, and through the help of so many others of you who have had the same experience. I was a nurse 30 years ago, and if talking about stool bothers you, then maybe you are in the wrong line of work. ??? Just saying. Thanks to everyone else for your helpful comments.

  45. #45 George
    Cherry Valley, MA
    September 23, 2015

    I had known that if you eat too much Twizzlers Black Licorice your stool will turn a bright green. Now I may have stumbled on yet another source. Too much grape Kool Aid can cause your stool to turn an ashen green. Wait until the nurses hear about this. (we are talking about a gallon of Kool Aid in a day. Scary but I was able to make the connection and confirm it on the web.)

  46. #46 Jennifer
    June 28, 2016

    1 bowl of Cap’n Crunch Crunch Berries will produce at least 1 green poo, possibly 2 green poos.

  47. #47 Nat
    United States
    November 30, 2016

    It’s amazing how we can all come together and discuss our poop…..like adults xD. Glad I found thisinteresting/hilarious site.