When poop smells like sulfur (rotten eggs, very “eggy,” or even like burnt rubber), it usually means your gut bacteria are making extra sulfur-containing gases, often from what you ate, medicines, or a gut issue.

What “sulfur poop” actually is

  • The smell often comes from hydrogen sulfide gas made by gut bacteria when they break down sulfur in foods and supplements.
  • A stronger-than-usual sulfur smell is common for short periods and doesn’t always mean something serious is wrong.

Think of it like this: your gut is a little chemical factory; give it more sulfur, and it will pump out more sulfur gas.

Common everyday causes

1. Foods high in sulfur

Eating a lot of sulfur-rich foods is one of the biggest reasons poop suddenly smells like sulfur.

Typical culprits:

  • Eggs (especially if you ate a lot recently).
  • Red meat and processed meats.
  • Garlic and onions.
  • Cruciferous veggies: broccoli, cauliflower, cabbage, kale, Brussels sprouts.
  • High-protein diets in general can also make stool and gas smell stronger.

If your sulfur smell started after a barbecue weekend, lots of eggs, or a new high-protein or keto-style diet, this alone could explain it.

2. Alcohol and drinks with sulfites

Alcohol—especially wine, beer, and cider—can intensify a sulfur smell.

  • These drinks contain sulfites and sulfates that gut bacteria convert into hydrogen sulfide gas.
  • Alcohol also irritates and speeds or slows your gut transit, which can change stool consistency and odor.

If your poop smells like sulfur after a night of drinking, this is a known pattern.

3. Supplements and medications

Some products can boost sulfur gas or upset your gut bacteria balance.

  • Iron supplements (like ferrous sulfate) can make stool darker and more sulfur-smelling.
  • Antibiotics can kill off some gut bacteria and let sulfur-producing ones dominate, changing odor.
  • Certain other medications and supplements can irritate the gut or alter the microbiome, also affecting smell.

Notice if the smell started after a new pill, vitamin, or antibiotic course.

When it points to a gut problem

Sometimes sulfur-smelling poop is a clue that your gut isn’t happy. The smell alone isn’t a diagnosis, but it matters alongside other symptoms.

4. Gut infections

Some infections cause very foul, sulfur-like stool.

  • Giardia (a parasite) can cause smelly, greasy diarrhea, cramps, and gas, often after drinking contaminated water or traveling.
  • Viruses like rotavirus (more in kids) can cause severe diarrhea with strong odor.
  • Bacterial infections or C. diff after antibiotics can cause watery, very smelly diarrhea and abdominal pain.

In these cases, the smell comes with clear signs: frequent diarrhea, pain, fever, or recent travel or antibiotic use.

5. Malabsorption and fat digestion issues

If your body isn’t absorbing nutrients or fats well, poop can be unusually smelly and odd-looking.

  • Stools may look pale, greasy, float, or be hard to flush, with a “chemical” or burnt-rubber smell.
  • Conditions like celiac disease, chronic pancreatitis, or bile acid issues can lead to this kind of stool.

This is more concerning if you also notice weight loss, fatigue, or chronic diarrhea.

6. Microbiome imbalance (dysbiosis, SIBO)

Your gut contains many types of bacteria, some of which specialize in breaking down sulfur.

  • If sulfur-producing bacteria become dominant, you can get more hydrogen sulfide and strong odors (sometimes described as burnt rubber or electrical smell rather than pure “eggy”).
  • This can happen with small intestinal bacterial overgrowth (SIBO), diet changes, stress, or after antibiotics.

People often notice bloating, gas, and shifting bowel habits along with the odor.

When to actually worry

Most of the time, sulfur-smelling poop passes in a day or two and tracks back to diet or minor gut upset. But you should pay attention if you notice:

  • Sulfur smell lasting more than 48 hours without any clear diet cause.
  • Ongoing diarrhea or very loose stools.
  • Strong abdominal pain or cramping.
  • Fever, chills, or feeling very unwell.
  • Blood in the stool or black, tarry stool.
  • Unintentional weight loss, fatigue, or pale/greasy stools that float.

In those cases, it’s time to contact a doctor or urgent care rather than just waiting it out.

If you’re pregnant and notice a new sulfur smell with bowel changes, you should call your doctor to be safe.

What you can try at home (short term)

These are general, non-emergency steps people often use to see if the smell improves:

  1. Look back 24–48 hours.
    • Did you eat a lot of eggs, meat, garlic, onions, broccoli, or cauliflower? Cut back for a few days and see if the smell improves.
  1. Scale down alcohol.
    • Avoid or reduce wine, beer, and cider for a bit; they’re common triggers for sulfur-smelling poop.
  1. Hydrate and go gentle on your gut.
    • Drink water, eat simple foods (rice, bananas, plain toast, boiled potatoes) if your stomach feels off.
  2. Notice any new medications or supplements.
    • If odor started with a new iron supplement, vitamin, or antibiotic, ask your doctor or pharmacist if this could be a side effect and whether you should continue.
  1. Watch for patterns.
    • Keep a brief log of foods, drinks, and symptoms to see if certain meals or habits always precede the sulfur smell. This can really help if you end up seeing a clinician.

Do not stop prescribed meds on your own—always clear changes with a healthcare professional.

Is “sulfur poop” an emergency?

Call a doctor or urgent care promptly if you have sulfur-smelling poop plus :

  • Severe or worsening abdominal pain.
  • High fever or feeling very ill.
  • Persistent vomiting or dehydration (dry mouth, dizziness, very dark urine).
  • Bloody stool, black/tarry stool, or mucus with pain.
  • Diarrhea that lasts more than a few days, especially with weight loss or weakness.

These signs can point to infection, inflammatory bowel disease, or malabsorption that needs testing and treatment.

TL;DR: “Why does my poop smell like sulfur?”
Most often: too many sulfur-rich foods, alcohol, or a temporary change in your gut bacteria from diet or meds. Sometimes: infection, malabsorption, or microbiome imbalance—especially if you also have pain, diarrhea, fever, or weight loss. If the smell doesn’t improve in about 48 hours, or you have any red-flag symptoms, it’s safest to check in with a doctor.

Information gathered from public forums or data available on the internet and portrayed here.