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Published on: 2/5/2026

"My Poop Smells Like Burnt Rubber": 3 Gut Issues That Cause This Bizarre Bathroom Symptom

A burnt rubber or chemical stool odor is most often linked to three gut issues: malabsorption of fats, sulfur-related digestion from diet or sulfur-producing bacteria, and microbiome imbalance such as dysbiosis or SIBO. There are several factors to consider, and this symptom is often manageable once the cause is identified, but persistent changes or any red flags should be evaluated by a clinician. For key warning signs, what to try now, and which tests and treatments might guide your next steps, see the complete details below.

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Explanation

My Poop Smells Like Burnt Rubber: 3 Gut Issues That Can Cause This Bizarre Bathroom Symptom

Noticing that your stool smells like burnt rubber or chemicals can be unsettling. While poop never smells pleasant, a sharp, acrid, or rubber‑like odor is different from normal and often points to something specific happening inside your digestive system.

The good news: in many cases, this symptom is explainable and treatable, especially when you understand the underlying gut issue. Below are three medically recognized gut problems that can cause this strange smell, explained in clear, practical terms—without panic, but without brushing things off either.


Why Stool Smell Matters

Stool odor is influenced by:

  • What you eat
  • How well you digest and absorb nutrients
  • The balance of bacteria in your gut (your microbiome health)
  • How fast food moves through your intestines

A burnt rubber smell usually comes from undigested compounds, especially fats or sulfur-containing substances, being broken down by gut bacteria in abnormal ways.


1. Malabsorption: When Your Gut Can't Absorb Food Properly

One of the most common medical reasons for a chemical or burnt rubber smell is malabsorption.

What Is Malabsorption?

Malabsorption happens when your digestive system does not properly absorb nutrients, particularly fats. Instead of being absorbed, these nutrients pass into the stool, where gut bacteria break them down and release strong-smelling byproducts.

Why It Can Smell Like Burnt Rubber

Poorly absorbed fats and proteins can create odors that are:

  • Acrid
  • Oily
  • Chemical-like
  • Similar to burnt rubber or plastic

This is often described as a sharp or industrial smell, not just "bad."

Common Causes of Malabsorption

  • Celiac disease (gluten-triggered intestinal damage)
  • Pancreatic enzyme insufficiency
  • Gallbladder or bile flow issues
  • Chronic intestinal inflammation

Other Signs You Might Notice

  • Pale, greasy, or floating stools
  • Diarrhea or loose stools
  • Unintentional weight loss
  • Bloating and gas
  • Fatigue or nutrient deficiencies

Malabsorption is not something to ignore long-term, because it can lead to vitamin and mineral deficiencies. A doctor can diagnose it with stool tests, blood work, or imaging.


2. Sulfur Overload: Diet and Sulfur-Producing Gut Bacteria

Another major cause of burnt rubber–smelling stool is sulfur.

How Sulfur Affects Stool Smell

Sulfur-containing compounds produce gases like hydrogen sulfide, which are responsible for:

  • Rotten egg smells
  • Chemical or rubber-like odors
  • Sharp, lingering bathroom smells

In some people, sulfur smells don't come across as "eggy" but instead as burnt rubber or electrical wiring.

Common Sources of Sulfur

  • High-protein diets
  • Red meat
  • Eggs
  • Dairy
  • Garlic, onions, and cruciferous vegetables
  • Protein powders and supplements

The Gut Bacteria Connection

Your gut contains bacteria that specialize in breaking down sulfur. If these bacteria become overactive or dominant, sulfur gas production increases. This is directly tied to microbiome health.

When Sulfur Smell Becomes a Problem

Occasional sulfur-smelling stool after certain meals is usually harmless. It becomes more concerning if:

  • The smell is persistent
  • It happens regardless of diet
  • It's accompanied by diarrhea, pain, or fatigue

In those cases, it may signal bacterial imbalance, food intolerance, or impaired digestion.


3. Gut Microbiome Imbalance (Dysbiosis or SIBO)

Your gut is home to trillions of bacteria. When that ecosystem is out of balance, it can dramatically change how your stool smells.

What Is Dysbiosis?

Dysbiosis means:

  • Too many harmful bacteria
  • Not enough beneficial bacteria
  • Bacteria growing in the wrong part of the gut

One specific type is Small Intestinal Bacterial Overgrowth (SIBO), where bacteria ferment food too early in digestion.

Why It Can Cause Burnt Rubber Smell

Imbalanced bacteria produce unusual fermentation byproducts, including:

  • Sulfur compounds
  • Fatty acids
  • Chemical-smelling gases

These can combine into an odor people often describe as burnt rubber, plastic, or metal.

Other Symptoms of Microbiome Imbalance

  • Excessive gas or bloating
  • Abdominal discomfort
  • Diarrhea, constipation, or both
  • Food sensitivities
  • Brain fog or fatigue

Factors that can disrupt microbiome health include antibiotics, chronic stress, restrictive diets, infections, and underlying gut disease.


When Smell Is a Clue—Not a Diagnosis

A strange stool smell alone does not diagnose a disease. However, persistent changes deserve attention, especially if they last more than a couple of weeks or come with other symptoms.

Red Flags That Require Medical Advice

Speak to a doctor promptly if you notice:

  • Blood in your stool
  • Black or tarry stools
  • Severe abdominal pain
  • Fever
  • Ongoing weight loss
  • Signs of dehydration
  • Symptoms that wake you from sleep

Some gut conditions can be serious or even life-threatening if untreated, so medical guidance matters.


What You Can Do Right Now

If you're experiencing these symptoms and want immediate guidance, you can get personalized insight by using Ubie's free Medically Approved LLM Symptom Checker Chat Bot, which helps you understand your symptoms and determine whether you should seek medical care.

That said, online tools are not a replacement for a doctor, especially when symptoms are ongoing or worsening.


Supporting Better Gut and Microbiome Health

While you wait to speak with a healthcare professional, general steps that often help include:

  • Eating a balanced diet with whole foods
  • Avoiding extreme elimination diets unless medically advised
  • Staying hydrated
  • Limiting ultra-processed foods
  • Being cautious with supplements and protein powders
  • Only using antibiotics when prescribed

If malabsorption, sulfur intolerance, or microbiome imbalance is suspected, targeted treatment—not guesswork—is the safest approach.


The Bottom Line

A burnt rubber smell in your stool is unusual, but it's often linked to:

  1. Malabsorption, especially of fats
  2. Sulfur-related digestion issues
  3. Poor microbiome health or bacterial imbalance

Many of these conditions are manageable once properly diagnosed. The key is not ignoring persistent changes and speaking to a doctor about anything that could be serious or life-threatening.

Your gut has ways of signaling when something's off. Paying attention—and getting professional guidance when needed—is the smartest next step.

(References)

  • * Blachier, F., et al. (2019). Hydrogen sulfide in the gastrointestinal tract: a new target for drug development? *British Journal of Pharmacology*, *176*(5), 651-663. doi: 10.1111/bph.14589.

  • * Pimentel, M., et al. (2020). Hydrogen Sulfide Small Intestinal Bacterial Overgrowth. *The American Journal of Gastroenterology*, *115*(9), 1391-1393. doi: 10.14309/ajg.0000000000000725.

  • * Likhodii, S., et al. (2018). Fecal volatile organic compounds as biomarkers of gut health and disease. *Metabolites*, *8*(3), 56. doi: 10.3390/metabo8030056.

  • * Lohr, J. M., et al. (2017). Exocrine pancreatic insufficiency: A neglected disease? *Digestive Diseases*, *35*(2), 127-133. doi: 10.1159/000450942.

  • * Ahmed, I., et al. (2016). Fecal Volatile Organic Compounds as Biomarkers of Inflammatory Bowel Disease. *Journal of Crohn's and Colitis*, *10*(10), 1214-1225. doi: 10.1093/ecco-jcc/jjw080.

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