The Science of Why Your Poop Smells So Bad

The Science of Why Your Poop Smells So Bad

Modern civilization has made impressive strides toward making humans smell tolerable. We have mouthwash for bad breath, deodorant for sweaty pits, and powder for our balls. But there's one bodily function where stank can't seem to be tamed.


The unmistakably foul smell of feces has plagued humankind for millennia. Perhaps you avoid pooping anywhere besides your home throne because you know what kind of damage your deuces can do.

We're proud to announce there's hope on the frontier of neutralizing the smell of your bowel movements. But first, we need to understand why poop stinks in the first place.

Why Does Poop Smell?

Everyone's poop smells like s***. Yes, even Instagram models drop deadly deuces. This is because all human beings undergo the same digestive process, starting with food entering your stomach, where it's mixed with digestive juices before moving into your small intestine.

The walls of your small intestine absorb water and nutrients into your bloodstream. The leftover waste goes into your large intestine, which has over 700 kinds of bacteria. Here, food substances mingle with organic compounds like skatole, sulfur, and fatty acids. 

By the time this putrid brew forms into poop that's ready to exit your rectum, it has a ripe stench that's all-too-familiar. (If you're wondering what your poop should look like, head over here).

4 Common Causes of Foul-Smelling Poop

No dude is immune from smelly poop, but certain factors can crank up the dial on the stank meter. 

Your Diet Is Loaded with Sulfur

The most common culprit of foul-smelling stools is your diet. Foods that are high in sulfur are notorious for producing deadly farts and equally deadly deuces. 

Sulfur is the third most abundant mineral in your body. It's essential for your body to function properly, but the downside is that it makes your bathroom reek like rotten eggs. Sulfur-rich foods include meat, fish, dairy products like ice cream, beans, and cruciferous veggies. 

Eating a sulfur-rich diet is healthy, but it's a surefire path to Stinkville. 

You Eat a Lot of Fat

High-fat diets can put your digestive system into overdrive. Fat is difficult for your body to break down, so those extra fat remnants that aren't absorbed go straight to the colon in an undigested state. This can result in rancid diarrhea with a very high-fat content, called "steatorrhea."

If you're wondering why people on the keto diet are having all kinds of weird poop problems, here's your answer.

Too Much Booze

Hangover poops aren't just explosive—they're toxic.

"High blood alcohol levels can affect the stomach and the small and large intestines—altering motility, the permeability of the intestinal wall, and the pre- and probiotics of the intestinal flora," says Christine Lee, MD, a gastroenterologist at Cleveland Clinic.

This can cause loose stool and diarrhea that smell worse than your standard dumps. 

"Alcohol has significant amounts of sulfate," says Dr. Lee. "The more sulfate consumed, the more it is available for colon bacteria to make sulfide gases, and sulfide gases can have an offensive stench."


Most guys poop once a day—give or take. But if it's been days since your last trip to the throne, there's a toxic stew of fecal matter brewing in your colon, which can cause bloating and abdominal pain. By the time your turd sees the light of day, it's so stinky you'll wonder how your body produced such a specimen.

Problems With Your Digestive System

There are a number of digestive health issues that can cause your poop to smell worse than usual. 

  • Malabsorption: a condition where the small intestine can't absorb enough nutrients. This can result in weight loss and extremely foul-smelling stools.
  • Lactose intolerance, which is an inability to process dairy products
  • Other food intolerances such as Celiac disease, which is a reaction to gluten that irritates the lining of the small intestine
  • Inflammatory bowel diseases (IBD), such as ulcerative colitis or Crohn's disease
  • Irritable bowel syndrome: a common disorder that affects the large intestine with symptoms include cramping, abdominal pain, and bloating.
  • Intestinal infections from a virus, bacteria, or parasite
  • Chronic pancreatitis when occurs when digestive enzymes start digesting the pancreas itself 

If you think you might be dealing with one of these gastrointestinal issues, contact your healthcare provider. Your doctor may ask for a stool sample, which can help pinpoint what's going on in your gut.

How to Stop Your Poop from Smelling

Spoiler alert: there's nothing you can do to make your excrement smell like a bed of roses. Some people might tell you to skip the late-night Taco Bell run or cut back on the beer. But a dude's gotta live (especially when covid is keeping us locked down). So we went into the lab and created an odor elimination solution that lets you leave the throne smelling better than you found it.

Forget nostril-piercing matches or air fresheners that only mask poo stank. DUDE Bombs create an indestructible barrier that traps odor in your toilet bowl and instantly neutralizes stank in the air. This 2-in-1 technology ensures that innocent bystanders never have to be victimized by your horrendous deuces.

Before you drop a bomb in your in-laws' bathroom, drop a DUDE Domb. You can literally walk around like your s*** don't stank.

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