Why Does Poop Smell? You Asked, We Answered

31 Jul, 2020

Woman smelling stinky poop.

I know you like to think your sh*t don’t stink but guess what? It does. And sometimes, it stinks real bad! Don’t worry. Everyone’s poop stinks. Yes, even Michelle Obama’s. But have you ever wondered why? What makes the foul stench of our bowel remnants reek with such otherworldly malodor! Let’s unpack this. 

How Poop is Made and Why It Smells

Before we start to investigate why poop smells, we should first have a solid ...or loose understanding (depending on what you ate today) of how poop is made. How about we take a quick journey through the digestive tract. 

After food enters your stomach, your stomach muscles mix the food and liquid with your digestive juices making something called chyme. That chyme is then emptied into your small intestines.

The muscles of the small intestine mix food with digestive juices from the pancreas, liver, and intestine, and push the mixture forward for further digestion. The walls of the small intestine absorb water and the digested nutrients into your bloodstream. The waste of the digestive process moves into the large intestine. 

The large intestine houses over 700 species of bacteria (seems crowded) that perform so many functions to make sure your body is getting all of its nutrients. The large intestine absorbs water from the chyme and stores feces until it can be defecated. Food products that cannot go through the villi, such as cellulose (dietary fiber), are mixed with other waste products from the body and become hard and concentrated feces.

The feces is stored in the rectum for a certain period and then the stored feces is eliminated from the body due to the contraction and relaxation of the anus. The exit of this waste material is regulated by the anal sphincter. 

The End. What a beautiful story. But that doesn’t explain that foul smell, does it. 

Well, the pungent smell of poop is due to something called skatole, which is an organic compound that is the primary odor of poop. That combined sulfur-containing compound called thiols, along with amines and carboxylic acids really gives your poop that smell that you can almost taste. Skatole is produced from tryptophan, that same compound found in turkey that makes you sleepy. 

It’s also interesting to note that smell is subjective. The perceived bad odor of feces has been hypothesized to be a deterrent for humans, because consuming or touching can cause sickness or infection. Human perception of the odor is contrasted by non-human animal's perceptions of it; for example, an animal who eats feces, like rabbits or your Doge, may be attracted to the smell of poop. 

Causes of Foul Smelling Stool

All poop smells. We’ve established that, however, sometimes it can give off a very different odor that may cause some alarm. #TFW you drop something so gnarly smelling that you have to clutch your own pearls. Those extra stanky ones can be triggered by a few different things. 


The most obvious reason is the food you’re eating. If you're eating a lot of sulfur-rich foods like eggs, dairy, meat and cruciferous veggies, your poops are going to smell deadly. 

A high-fat diet may overwhelm your digestive system, and your gut may not be able to break down all the fat consumed. Unbroken down fat that can’t be absorbed, will pass to your colon undigested leaving you to deal with smelly diarrhea with a very high fat content. 


Some medications can cause gastrointestinal diarrhea. Taking some over-the-counter multivitamins may also cause stinky poops if you’re allergic to the supplements’ ingredients.

After taking antibiotics, you may have stanky sh*ts until your bacteria flora is back to normal. Smelly diarrhea can be a side effect of taking more than the recommended daily dose of a multivitamin or any single vitamin or mineral. Too much of any of these vitamins can have life-threatening effects: 

  • Alpha lipoic acid
  • Chondroitin sulfate
  • DMPS
  • DMSO
  • Epsom salts
  • Garlic
  • Glucosamine sulfate
  • Magnesium sulfate
  • Milk thistle
  • MSM
  • N-acetyl cysteine (NAC)
  • Taurine
  • Vitamin A
  • Vitamin D
  • Vitamin E
  • Vitamin K


    • diff, is a bacterium that can cause symptoms ranging from diarrhea to life-threatening inflammation of the colon. Illness from C. difficile can cause poops to smell extremely bad. There are a number of diseases that funky poops can be attributed to. 
    • Celiac disease 
    • Crohn disease
    • Chronic pancreatitis
    • Cystic fibrosis
    • Intestinal infection
    • Lactose Intolerance
    • Malabsorption
    • Short bowel syndrome
    • Blood in stool from stomach or intestine

    Call your health care provider if you have black or pale stools often, blood in your poop, changes in your bowels movements related to your diet, chills, cramping, fever, pain in the abdomen, or weight loss. 

    Frequently Asked Questions (FAQs)

    Chances are you can across this article by google “why does my poop stink?” You’re not the only one. In fact, some people have taken that question a step further with the specifics, so we are going to answer these burning questions for you. Here are some frequently asked questions related to “why does my poop stink?”

    Why does poop smell like sulfur?

    If your poop smells like sulfur, the odds are that you are eating foods that have a high-sulfur content. Eating cruciferous veggies like broccoli, cauliflower, Brussels, asparagus, and cabbage could result in some unpleasant smelling bathroom experiences. Red meat, poultry, fish, pork, and eggs can all make your doodoo smell sulfur-y, too, along with dairy.

    And if you love to add garlic and onions to your meal, you better believe they’re going to make your poop stink too. You might love seasoning vegetables and meats with onions and garlic, but those can lead to sulfuric ass-id. 

    Why does my poop smell fishy?

    The major symptom of cholera is severe diarrhea with poops that smell fishy. If you suspect that you have cholera, don’t worry. This isn’t the 1800s. The most important thing to do is rehydrating and replenishing your fluids. If your diarrhea is extreme, it’s wise to seek medical attention. 

    Why does poop smell sweet?

    “Sweet smelling” poop?! Yes, it can happen. But it’s not the type of sweet that you’d want to eat. It’s the kind of sweet that’s similar to how horse sh*t smells. It is most likely caused by the bacterial infection, Clostridium difficile also known as C. Diff.


    Poop smells. It always has and it always will. But you know what your poop normally smells like, so if you notice any extreme changes in your odor, your body may be trying to tell you something. And just because your poop stinks, your butt doesn’t have to. TUSHY’s Modern Bidet Attachment will make sure your poop stench doesn’t follow your butt around once you’ve let it go.