Why Does My Poop Smell Like Coffee?

crazy by Editorial Staff | Updated on April 26th, 2023

Does your poop smell like coffee? If so, you’re not alone! Many people experience this phenomenon, and it can be quite alarming.

In this blog post, we will discuss the possible causes of why your poop smells like coffee. We’ll also provide some tips on reducing any unpleasant odors in the future.

coffee beans in a shape of shit. blue background

What causes poop to smell like coffee?

Several possible causes for poop smelling like coffee. If your poop smells like coffee and persists for over a few days, it’s important to consult a doctor as soon as possible to determine the underlying cause. Here are some possible causes why your poop smells like coffee.

Phenylthiocarbamide sensitivity

Phenylthiocarbamide (PTC) sensitivity is a genetic trait affecting how we perceive certain smells. People sensitive to PTC are likelier to detect the coffee smell in their poop. Some studies have found that up to 70% of people sensitive to PTC can smell coffee in their poop.

This trait is more commonly found in people of European descent but can also be found in other populations. PTC sensitivity may also be linked to certain food allergies, and it’s important to speak with your doctor if you think you may have this condition. Certain foods like garlic, onions, and cruciferous vegetables may also cause your poop to smell like coffee due to their sulfur content.

Foods that can make your stool smell like coffee

Certain foods can cause your stool to smell like coffee, such as coffee itself, garlic and onions, red meat, and high-fiber foods. It is important to be aware of the dietary causes of coffee-smelling stools to make healthier eating choices if you have an unpleasant-smelling stool.


Coffee is one of the most common culprits for a stool that smells like coffee. When you drink coffee, polyphenols are absorbed by the digestive tract and expelled through the stool, creating a distinct smell. If you consume large amounts of coffee and your stool is consistently smelling like coffee, it may be worth cutting back on your intake or looking for alternatives such as decaf or herbal teas.

Garlic and onions

Garlic and onions are two foods that can cause your stool to smell like coffee. Eating too much of these sulfur-rich vegetables can cause the body to produce sulfide gases, which can be released from your stool and cause a coffee-like smell.

Suppose you suspect garlic and onions may contribute to your coffee-smelling stools. In that case, you must consult your doctor or gastroenterologist for advice on adjusting your diet accordingly.

Red meat

Red meat contains high sulfur, making your stool smell like coffee. Eating large amounts of beef, lamb, and pork can result in your stool having a strong, unpleasant smell. 

High-fiber foods

High-fiber foods are one of the most common causes of foul-smelling stools. Fiber is a carbohydrate not easily broken down by the digestive system, so it passes through the gut quickly and can cause loose stools that have a strong odor. Foods high in fiber include whole grains, fruits, vegetables, and legumes.

Eating too much fiber can also cause an overgrowth of bacteria in the intestines, leading to increased gas and foul-smelling stools. If certain high-fiber foods cause your stool to smell like coffee, it is best to consult a gastroenterologist to determine the underlying cause and seek appropriate treatment.


Alcohol consumption has been linked to causing a coffee-like smell in poop. When alcohol is consumed, it can contain significant amounts of sulfate, which is available for colon bacteria. This can cause the stool to produce a foul odor. 

Medications that can make your stool smell like coffee

In addition to dietary changes, medications can also affect the smell of your stool. Iron supplements, antibiotics, acid reducers, and painkillers are all medications that can cause your stool to smell like coffee. 

Iron supplements

When the body does not get enough iron, it cannot produce enough red blood cells to keep itself healthy. This is called iron-deficiency anemia, and lack of iron can cause your stool to be darker in color and have an unpleasant odor.

Iron supplements are one of the most common medications that can cause your stool to smell like coffee, so if you’re taking them, be sure to monitor your stools for any changes in color or odor.


Antibiotics are commonly prescribed to treat infections, but they can also affect the body, making your stool smell like coffee. Antibiotics disrupt the delicate balance of good and bad bacteria within the gut, resulting in temporary stomach upset and smelly stool.

Furthermore, antibiotics can lead to an overgrowth of C. difficile, which can cause diarrhea that some say smells sickeningly sweet. 

Acid reducers

Acid reducers are commonly prescribed medications used to reduce the amount of acid the stomach produces. Common acid reducers include antacids such as sodium bicarbonate and proton pump inhibitors (PPIs).

These medications often treat heartburn, GERD, and peptic ulcer disease. If a person is taking an acid reducer, it can cause their stool to smell like coffee. This is due to the fermentation of indigestible sugars found in some medications and the interaction between these sugars and other components of the digestive system. 


Painkillers can also be a cause of coffee-smelling stool. Certain painkillers, including ibuprofen, naproxen, and aspirin, can affect the bacteria in the digestive system and lead to an unpleasant-smelling stool.

It’s important to talk to your doctor before taking any over-the-counter medications, as they can have unexpected side effects and interact with other medications you might be taking. If you’re already taking painkillers and your stool starts to smell like coffee, it could be a sign that the medication is causing issues with your digestive system.

Medical Conditions

Medical conditions can be a factor in why your stool smells like coffee. IGastroenterologists can help diagnose and treat any conditions you might have, so be sure to talk to your doctor if you experience any changes in your stools.

Irritable Bowel Syndrome (IBS)

In some cases, foul-smelling stools have a putrid and rotten odor which IBS may cause. Irritable Bowel Syndrome (IBS) is a common disorder of the digestive tract that can cause recurring abdominal pain, constipation, and diarrhea.

Symptoms of IBS include stomach cramps, bloating, and changes in bowel habits. It is important to note that although the symptoms may change over time, IBS is often a lifelong condition. High-fiber foods, alcohol consumption, and certain medications can all cause a coffee-like smell in your poop if you suffer from IBS. 

Small Intestinal Bacterial Overgrowth (SIBO)

If your poop smells like coffee, it could indicate an underlying medical condition related to SIBO. Small Intestinal Bacterial Overgrowth (SIBO) is a condition that occurs when there is an overgrowth of bacteria in the small intestine.

It can cause gastrointestinal symptoms, such as gas, abdominal pain, bloating, nausea, oily stools, and diarrhea. Consulting with your doctor is the best way to determine the underlying cause and explore treatment options.

Celiac Disease

Celiac disease is an autoimmune disorder that can cause a person’s stool to smell like coffee. It is triggered by ingesting gluten, wheat, rye, and barley protein. People with celiac disease have an immune response to gluten which causes inflammation in their intestines, resulting in abnormal digestion.

This can cause the body to be unable to absorb certain vitamins and minerals, leading to nutritional deficiencies. It can also cause gut bacteria changes, affecting the smell of your poop. Symptoms may include bloating, abdominal pain, and fatigue.

Diagnosis is typically made through blood tests and a small intestine biopsy. Treatment includes following a strict gluten-free diet and avoiding all sources of gluten to reduce symptoms and prevent further damage to the intestines.

Colon Cancer

Colon cancer can cause changes in your stool, including a foul-smelling odor. It is important to be aware of the symptoms associated with this disease, such as changes in bowel habits, abdominal pain, and blood in the stool.

Contact your healthcare provider immediately if you are experiencing any of these symptoms. It is recommended to get screened for colon cancer starting at age 50. Eating a high-fiber diet and limiting alcohol consumption can help reduce your risk of developing colon cancer.


There are many potential causes for why your stool may smell like coffee, ranging from dietary changes to various medical conditions. If you are experiencing foul-smelling stools, consult your doctor to determine the underlying cause and get appropriate treatment.

Eating certain foods and taking medications can also affect the smell of your stool, so be mindful of what you eat and take. If you are concerned about the smell of your poop, practice good hygiene habits and ensure a balanced diet.

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Disclosure: No compensation or free products were received in exchange for writing this review.


Editorial Staff

The editorial staff at Crazy Coffee Crave is a team of coffee enthusiasts & Baristas who enjoy the one thing we all think about as soon as we get up in the morning. Trusted by thousands of readers worldwide.