Why Poop smells like metal – What you need to know!

  • By: Editorial Team
  • Date: February 25, 2022
  • Time to read: 8 min.

Why does my poop smell iron-y?

It’s the question nobody wants to ask, but everybody desperately needs to know.

The Huffington Post recently ran a piece that attempted to answer this very question, and it turned out that everyone was wrong.

What you think is making your poop smell like iron or metal is probably not what’s actually behind your stench-filled excretions.

According to HuffPo’s Bobby Olivier , “If your stool smells like metal…it may be because of something you’re eating.” He cites coffee as an example, noting that caffeine can lead to “a particularly pungent smelling bowel movement.”

This sounded bizarrely specific to us, so we did some digging into the actual science. Turns out that there are several other reasons why poop smells like metal , and coffee isn’t necessarily one of them.

If you can believe it, there’s something even more disgusting than poop that smells like metal: actual metal . According to doctors in a 2010 study in the International Journal of Microbiology, certain intestinal parasites (specifically the human botfly) can actually give off a metallic odor “similar to that found in scented candles.” Yuck.

This is bad news for those who love fiery wings and double IPAs, because foods such as curry and beer can make your bowel movements smell like iron . But once again, this isn’t exactly why your stools might be stinking up your bathroom.

coffee beans on white plate

What different poop smells mean?

Instead of metal, your poop might be smelling like sulfur . A food intolerance to lactose or a sensitivity to foods containing the sugar alcohol sorbitol could leave you with poop that smells like rotten eggs, says Dr. Joseph Lee , an assistant professor of gastroenterology at Harvard Medical School and Beth israel Deaconess medical Center.

“Sorbitol, which is often contained in sugar-free gum and toothpaste, can cause diarrhea,” explains Lee. “If you’re intolerant to lactose (the sugar in dairy products), then your body lacks an enzyme to break down this type of sugar.”

As a result, you wind up pooping out undigested sugars. Those sugars ferment inside your intestines and release gases, which may have an odor that some find to be sulfurous.

If you’re on certain medications, your poop might stink because of what’s not in the medicine. A new study published in the journal npj Schizophrenia found that people with schizophrenia had heightened sensory perception compared to others without the mental disorder. Researchers noted that some medications given for schizophrenia can make a person less sensitive to smells.

Why does my poop smell like Sulphur?

It could also be a sign of some bacteria imbalance in your gut microbiome . That’s according to Dr. Robynne Chutkan , a gastroenterologist and author of ” The Microbiome Solution .” “When the balance of species inhabiting your gut is disrupted, certain molecules can be produced that have an odor,” says Chutkan. In other words, if you’re lacking good bacteria in your digestive tract, bad bacteria might take over, causing changes to the chemicals inside your intestines. These changes can create a new scent similar to rotten eggs or metal.

Some people with IBS report having more gas and smelling their poop more than normal after eating foods containing fermentable fiber . This is because these types of fibers feed the bacteria in your gut, which ferments them and causes odor.

“This is not true of everyone with IBS, but some people are more sensitive to the effects of fermentable fiber,” says Chutkan. “For these individuals, reducing intake of foods containing fermentable fiber can decrease gas production and minimize over-excretion of stool components that cause malodorous flatus.”

People who have had weight loss surgeries may experience a similar effect . These changes in the digestive system can also lead to excess gas and cause food to be broken down differently by bacteria in the intestines, so its odors can be altered. This means that your poop might smell rank after you’ve gone through this type of operation.

Why do I smell metal and taste metal?

Nerves that connect to your brain might be responsible for the metallic tastes you experience when you go number two. This is most commonly seen “in people with neuropathies [which affect or damage nerves], but it can also occur in healthy individuals,” says Dr. Catherine O’Brien , a gastroenterologist at Kaiser Permanente in San Francisco.

In other words, if your nervous system isn’t sending signals properly, you could sense weird things from your poop including a metal taste or smell.

“Parasitic infections and diseases of the stomach and intestines can damage the protective coating on nerve fibers,” explains O’Brien, which allows electrical impulses to leak out and create abnormal sensations such as tasting metal when going to the bathroom.


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Why is my poop green?

“If you see bright or dark green poop, there’s cause for concern,” says Lee. According to the American Gastroenterological Association , this may be a sign of either a parasitic infection such as giardiasis (which causes diarrhea and gas) or inflammatory bowel disease (a serious condition that affects your digestive system). They recommend seeing a doctor immediately if you experience bright or dark green stools.

brown wooden padlock on brown metal wire

What does it mean if I smell like bleach when I poop?

Chlorine and other chemicals in tap water can make their way through your intestinal wall and into the blood stream, causing an odor in some people. “This problem has been seen more often western countries because we use more chemicals in our water, but it can occur anywhere,” says O’Brien.

There are a few ways to spike the scent of your feces if this is something you’re dealing with. The first step is to reduce chemical exposure by drinking purified or filtered water rather than tap. Then, “putting more vegetables into your diet can help create bulkier stool that causes gas which leads to flushing out of molecules that might cause odor,” says O’Brien. If these changes don’t make a difference, talk to your doctor about medications for constipation or possible dietary supplements that could help.

A parasite infection can also lead to smelling like bleach after pooping according to the Mayo Clinic .

Why do I keep smelling copper?

Copper is often found inside fruits and vegetables, so it’s not surprising that smelling this metal after going number two could be a result of breaking down compounds from healthy foods in your digestive system.

“Bacteria release gasses as they break down food,” explains O’Brien. “These gasses can have a metallic odor.”

In some cases, however, you might experience the smell of copper more intensely than usual. In those cases, this may signal some sort of infection or disease . If your diarrhea or vomiting doesn’t improve within a few days, reach out to a doctor for advice on getting checked out.

Why do I smell iron?

Iron is a chemical which exists in two forms: ferrous and ferric. The element can be detected in the form of ferrous ions which are derived from salts such as potassium ferrocyanide, sodium hydroxide and ammonium iron(II) sulfate. Iron is also found in the form of ferric ions that come from salts containing iron(III) or iron(IV). For example, these include copper sulfate and sodium phosphate. The results will vary depending on the chemical used for testing.

The human body emits an odor similar to that of blood when cutting certain vegetables such as cabbage, onion, celery or when consuming strong spices such as garlic or nutmeg. This is caused by organic substance called isovaleric acid contained in the vegetables. During digestion, bacteria act on these organic substances to generate isovaleric acid. The gas penetrated through the lungs will be excreted by exhalation which produces an odor similar to that of blood.

Isovaleric acid does not exist in fresh vegetables but only when they are broken or damaged. This causes the formation of various components derived from amino acids forming an unpleasant smell similar to acetic acid or vinegar, which also causes a bitter taste.

The intensity of this smell increases during cooking because complex reactions occur with water and sugars in the food generating more molecules containing sulfur compounds such as methyl mercaptan, dimethyl sulfide and dimethyl disulfide leading to stronger flavors resembling garlic.

What do you smell before you have a stroke?

Before a stroke, patients can often smell blood and metal as if they were some sort of animal prey. If you’ve ever heard someone say that their loved one complained of such things right before or during a stroke, it’s not just out of the blue. The person really was smelling these things either because they tasted them in their food or smelled them on their bodies after eating the food. It’s part of a condition called “sensory misperception.”

That isn’t to say that people who experience sensory misperception are crazy; it simply means that there is some neurological damage taking place where the brain has trouble processing what the senses are actually telling it. In the case of pre-stroke sensory misperception, research shows that this may be the result of damage to the insular cortex, which is responsible for processing taste and smell.

According to a study in Neuroscience Letters: “The patient complained about persistent symptoms of food cravings (sweet and sour) and intense oral pain (burning and metallic taste). She was disoriented in time. Magnetic resonance imaging showed an infarct involving all parts of the right insula.”

Another study from Frontiers in Neurology notes that 27 percent of stroke patients report these symptoms before their strokes actually occur. The paper goes on to say that such sensory misperceptions should be considered as clinical symptoms of impending stroke. This means you should take them very seriously and get help immediately if you experience them yourself or see them in others.

Why can’t I smell anything?

It could be the case of anosmia, better known as “lack of sense of smell.” If you can’t smell anything, it’s possible that there is no one single cause. Also, it could be due to some damage or obstruction of your nasal passages physically preventing particles from reaching your olfactory nerves (the nerve responsible for sensing odors). It may also be due to some damage in the brain itself which prevents any signals sent by the nose from being processed properly.

brown nose artwork on white wooden shelf

In most cases, people who have anosmia don’t realize that they actually do have a sense of smell because they’ve been without it since birth. In other words, their brains never developed the ability to process smells. However, if something damages this area of the brain, that person will then realize that they actually do have some sense of smell after all, but they simply never knew it.

Why I feel like I’m smelling blood every now and again?

It could be caused by epilepsy or “Grand Mal” seizures which can cause feelings like you’re smelling blood. This is because during a seizure, the limbic system (the area in your brain responsible for emotions) becomes extremely active so much so that it actually over-rides other areas of the brain. This causes a variety of sensory phenomena to occur including hallucinations which can include smells such as burning rubber or metal.