Why Your Poop Smells So Bad: Causes & How to Fix It

Key takeaways:

• Occasional foul-smelling poop is common, but persistent odor can signal something more.
• Some foods, medications, or digestive conditions can lead to smellier stool.
• Knowing when to check with a doctor can help you stay on top of your health.

Let’s face it—everyone deals with smelly poop at some point. For the most part, it’s normal and can depend on what you ate, how well your digestive system works, or even recent changes in your routine. But if your poop has a particularly strong, unpleasant smell consistently, it could mean something else is going on.

In this article, we’ll take a closer look at the causes of foul-smelling poop, including what’s normal and what’s not, as well as treatment options. We’ll also cover when to talk with a healthcare provider to ensure everything’s okay. Let’s dig into some common questions to help you understand more about what’s happening.

Is it normal to have foul-smelling poop?

Yes, having foul-smelling poop from time to time is quite common. Foods rich in certain compounds, like sulfur, can add a strong odor. Certain high-protein foods, spices, and vegetables like broccoli or garlic can lead to smellier bowel movements. Medications, including antibiotics, can also cause a temporary change in odor by affecting your gut bacteria.

If you notice a persistent, strong, or unusual odor, it might hint at an imbalance or a health issue. When foul-smelling poop becomes a regular occurrence, it could mean your body isn’t fully absorbing nutrients, or it might indicate an infection. Keeping track of other symptoms or any noticeable patterns can help identify potential concerns.

Causes of foul-smelling poop

Foul-smelling poop can have several causes. Here are some common culprits:

Dietary choices

Certain foods, especially those high in sulfur or protein, can make stool smell stronger. Foods like red meat, eggs, and vegetables like cabbage and broccoli contain sulfur, which can cause a noticeable odor when broken down in the gut.

Food intolerances

If you’re intolerant to foods like lactose (found in dairy) or gluten (found in wheat and certain grains), your body may struggle to digest them fully. This can lead to gas, bloating, and particularly smelly bowel movements.

Infections

Infections in the digestive tract, such as a bacterial or viral infection, can cause inflammation and lead to foul-smelling poop. Common culprits include infections caused by E. coli or Giardia, which may cause other symptoms like diarrhea, cramps, and nausea.

Malabsorption disorders

Conditions like Celiac disease, Crohn’s disease, or chronic pancreatitis can affect your body’s ability to absorb nutrients, causing fats and undigested foods to pass through your digestive tract. This can result in stool that’s bulky, oily, and strong-smelling.

Other causes of foul-smelling poop based on another condition or situation

Sometimes, certain situations or health changes can lead to a temporary or unique change in stool odor. Here’s a look at some specific cases:

Foul-smelling poop while pregnant

Hormonal changes and shifts in digestion during pregnancy can alter bowel movements and sometimes cause stronger smells. Constipation or changes in diet during pregnancy might also play a role.

Foul-smelling poop while menstruating

Hormone fluctuations during menstruation can impact the digestive system, leading to constipation, diarrhea, or changes in stool odor for some people.

Foul-smelling poop after drinking alcohol

Alcohol can irritate the digestive tract, and it often leads to dehydration, which can make stool harder and smellier. Drinking alcohol can also disrupt the natural balance of gut bacteria, which may contribute to unusual odors.

Foul-smelling poop after surgery

After surgery, especially digestive surgeries, your body may take time to adjust. This can result in temporary changes in digestion and stool smell. Pain medications and antibiotics can also impact gut health and cause odor changes.

Foul-smelling poop after a colonoscopy

Sometimes, a colonoscopy can temporarily disrupt the balance of gut bacteria, especially if you’ve taken a laxative prep beforehand. Some people may notice a difference in odor until the gut microbiome settles again.

Read our guides on different types of stool, stool colors, and healthy vs. unhealthy stool for more.

Treatment options for foul-smelling poop

If you’re dealing with unusually smelly poop, there are several options that may help improve digestion and reduce odor.

Adjust your diet

Diet plays a significant role in the smell of bowel movements. Foods high in sulfur, such as garlic, onions, and red meats, can increase stool odor. If you suspect these foods may be contributing, try reducing them in your diet and incorporating more fiber-rich foods like fruits, vegetables, and whole grains.

Fiber supports healthy digestion and can help reduce odor by moving waste through your system more efficiently. Additionally, fermented foods like sauerkraut and kimchi are great for gut health and can help balance bacteria in your digestive tract.

Take probiotics

Adding probiotics to your diet may improve the balance of gut bacteria, which can help reduce foul smells. Probiotics are live bacteria that support a healthy gut environment, often found in foods like yogurt, kefir, and other fermented items, and in supplement form.

By encouraging the growth of beneficial bacteria, probiotics may improve digestion and make bowel movements less odorous. If you’re new to probiotics, start with small amounts and increase gradually to give your body time to adjust.

Hydration

Proper hydration is essential for effective digestion. Drinking enough water helps soften stool and prevent constipation, making it easier for your body to process waste efficiently. When you’re well-hydrated, your digestive tract can function smoothly, which may reduce unpleasant odors.

Aim for at least 8 glasses of water daily, and consider herbal teas or water-rich foods like cucumbers and melons to help meet your hydration goals.

Digestive enzymes

For some people, digestive enzymes can aid in breaking down foods that may otherwise cause odor. These enzymes, found naturally in foods like pineapple and papaya, help your body digest fats, proteins, and carbohydrates more effectively.

Supplements containing digestive enzymes are also available, but consult a healthcare provider before starting them to ensure they’re a good fit for you.

Limit processed foods and sugars

Processed foods and sugars can disrupt the balance of bacteria in the gut, sometimes leading to digestive issues and foul-smelling poop. By reducing processed foods and opting for whole, nutrient-rich alternatives, you support better digestion and overall gut health.

When you should see a doctor about foul-smelling poop

Most of the time, a change in stool smell isn’t a big deal, but sometimes it’s best to get it checked out.

You should see a doctor if:

• The smell is persistent and unusual, with no obvious cause.
• There’s an ongoing change in stool color, texture, or frequency.
• You experience additional symptoms like abdominal pain, nausea, or bloating.
• There’s a small amount of blood in your stool.

You should go to the emergency room if:

• There’s a significant amount of blood in your stool.
• You have severe abdominal pain that doesn’t go away.
• You’re experiencing signs of dehydration or fever along with diarrhea.

Questions to ask your doctor about foul-smelling poop

If you decide to consult a doctor, here are a few questions that can help you get the best care:

• Could my diet or medications be causing these changes in stool odor?
• Are there specific tests that could help identify the cause?
• What dietary changes could help reduce the odor?
• Could this odor be a sign of an underlying health condition?

Frequently asked questions: poop with a foul odor

Many people have questions about what causes foul-smelling poop. Here are answers to a few common ones:

Does Celiac disease cause poop with a foul odor?

Yes, Celiac disease can cause foul-smelling stool. When someone with Celiac disease consumes gluten, their immune system reacts by damaging the lining of the small intestine. This affects nutrient absorption, particularly fats, which can lead to foul-smelling stools that are often bulky, greasy, and difficult to flush.

Managing Celiac disease by strictly avoiding gluten is essential and can help reduce odor and other digestive symptoms.

What infections cause foul-smelling poop?

Several infections can lead to foul-smelling poop. Bacterial infections from pathogens like E. coli and Salmonella, as well as parasitic infections like Giardia, can cause an unpleasant odor and symptoms like diarrhea, cramping, nausea, and sometimes fever.

These infections are often acquired from contaminated food or water. If you suspect one of these types of infections, it’s best to consult a doctor, as they may require treatment to prevent dehydration and complications.

What does diabetic poop smell like?

For people with uncontrolled diabetes, stool can develop an unusual odor due to high blood sugar levels affecting digestion. When blood sugar levels are elevated, the body may produce ketones—chemicals that are released when the body breaks down fats for energy instead of using glucose.

This can result in a distinctive smell. Properly managing diabetes with the help of a healthcare provider can help improve digestion and reduce any unusual odors in stool.

Managing foul-smelling poop

Dealing with occasional smelly poop is a common part of life, especially after eating certain foods or if your gut bacteria temporarily shift. But if the odor becomes consistent, sour, or highly unusual, it may signal an underlying issue worth investigating.

Monitoring your diet, staying hydrated, and paying attention to any other digestive symptoms—such as bloating, cramps, or changes in stool consistency—can help you spot patterns and make adjustments.

General Medicine follows a strict editorial process, including using real experts to write our articles, vetted primary sources, fact-checking, a secondary medical review, and updates as necessary. This article was medically reviewed and fact checked by Dr. Pallabi Sanyal-Dey, MD.

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