Let’s be real: Poop always smells pretty bad. To hide the stench, you likely keep a stash of air freshener in your bathroom. But, on occasion, you might notice that your poop is extra stinky, leading you to wonder: Why does my poop smell so bad? “It is common knowledge that the smell of poop is unpleasant,” says Dr. Evelyn Darius, MD, a primary care physician at virtual health platform PlushCare. However, stool with particularly pungent smells can signal an underlying medical issue. Along with a medical condition, the odor of your poop can be influenced by what you eat, what medications you’re taking, or a food allergy. Parade.com asked medical experts to explain why your poop smells so bad sometimes, and when you should worry about it.
You eat a lot of foods containing sulfur
Foods rich in sulfur, like meat, cheese, eggs, and cruciferous vegetables including broccoli, cauliflower, and Brussel sprouts, can make your poop smell more pungent, says Susan Wong, RN, BSN, also known as “Nurse Wong,” host of Butt Talks TV and author of “The Power of Pooping.” “Poop odor is related to the fermentation from the breakdown of waste products,” she explains. These sulfur-rich foods are harder to digest than others, which means your gut has to work a little harder and produces excess stinky gas in the process.
You’re drinking too much alcohol or eating junk food
Drinking alcohol can affect your bowel habits. For some people, it can cause loose stools, and others constipation. Cocktails, beer, and wine can also be high in sulfates, which can make you gassy. Wong says drinking alcohol can be dehydrating, which can affect the stench of your poop. Processed foods that are high in fat and sugar can be tough to digest, so they stay in your system longer, creating more gas. These foods may also contain a range of chemicals that can affect your bowel habits.
You might have an infection
Infections from bacteria, viruses, and parasites can cause inflammation in the gastrointestinal tract. The infections could lead to symptoms like watery, foul-smelling stool, Darius says, as well as abdominal cramps, pain, and fever.
You could be lactose intolerant or have a milk allergy
Consuming lactose, the sugar found in milk products, can cause loose, foul-smelling stool, Darius says. People who are lactose intolerant don’t produce enough lactase, the enzyme in your body that digests dairy, so these foods are difficult to digest. A milk allergy may cause your poop to smell bad, too. Milk allergies aren’t the same as lactose intolerance. When you have an allergy, your immune system overreacts to certain food proteins.
You could have a GI condition or other illness
Several conditions, like celiac disease, ulcerative colitis, Crohn’s disease, irritable bowel disease, and chronic pancreatitis, lead to bad-smelling poop. Darius says many of these conditions cause malabsorption, which is when the body can’t absorb some nutrients, like fats, protein, or carbs. The nutrients that go undigested can take on a strong, smelly odor when you poop.
You’re taking certain medications or supplements
Some over-the-counter medications and supplements, like fish oil and multivitamins, may make your poop extra stinky, Wong says. That’s especially true if you consume too much of vitamins, like A, E, and K, which can upset your stomach. Taking antibiotics can cause foul-smelling poop, too. The medications can negatively affect the gut microbiota, making your poop smell bad until your gut bacteria get back to normal.
When to see a doctor about your smelly poop
If your poop’s normal odor doesn’t return in a day or two, it’s a good idea to check in with your doctor—especially if you have black, pale, or bloody stools, cramps, fever, chills, weight loss, or pain in your abdomen. Your doctor may want to test your stool to determine what may be causing your poop to smell so bad, such as an infection. Wong says a GI specialist can also rule out more serious medical conditions, like IBS or diverticulitis. Also, visit your doctor if you’re chronically constipated with abdominal pain and bloating, she says, “because your digestive system may be out of balance and you need medical assistance.” Next, read about some reasons why it might hurt to poop.
Sources:
Dr. Evelyn Darius, MD, a primary care physician at virtual health platform PlushCareSusan Wong, RN, BSN, also known as “Nurse Wong,” host of Butt Talks TV and author of “The Power of Pooping” Cleveland Clinic: Lactose Intolerance American College of Allergy, Asthma, & Immunology: Milk Allergy Cleveland Clinic: Irritable Bowel Syndrome (IBS)Mount Sinai: Stools - foul-smelling
