The Real Reasons Why Your Poop Is So Smelly

Poop smells. That’s a fact of life. But sometimes, your poop can smell especially foul, and that may leave you wondering what’s going on. There are a number of reasons why your stool might emit a particularly putrid odor. Understanding the potential causes can help you get to the bottom of the problem (no pun intended).

What Gives Poop Its Smell?

Before exploring why poop may smell worse than normal, it helps to understand where the typical poop odor comes from in the first place. The smell is mainly caused by sulfur-containing gases produced by your gut bacteria as they break down food that’s passed from your small intestine into your large intestine.

The bacteria release gases like hydrogen sulfide, methyl mercaptan, and skatole. These are the main culprits behind poop’s distinctive bouquet. The specific makeup of your gut microbiome and the foods you eat determine the particular volatile organic compounds present and just how stinky things get.

When Poop Smell Is Worse Than Normal

While some smell is perfectly normal, an exceptionally foul odor can be a sign that something is off. Here are some potential reasons your poop smells significantly worse than usual:

• Diet – Foods like red meat, broccoli, cauliflower, dairy, and eggs contain sulfur and can make your poop more odorous. Garlic, onions, spices, and cruciferous veggies may also contribute. Eating more of these foods than normal can intensify the smell.
• Constipation – When stool sits in the colon for longer than usual, bacteria have more time to work on it, producing extra gas and a stronger aroma. Constipation can create little hard poop balls that have concentrated odor.
• Diarrhea – Watery diarrhea still contains the same smelly gases. Some causes of diarrhea may also change your gut environment, affecting your microbiome makeup and gas production.
• Infection – Bacterial infections can upset the natural balance of microbes in your gut, leading to worse smelling gas and poop. Infections may also cause diarrhea. Common culprits include Salmonella, Campylobacter, Clostridium difficile, and E. coli.
• Inflammatory bowel disease – Chronic conditions like Crohn’s disease and ulcerative colitis promote inflammation in the intestines, which can change gut bacteria activity and digestion. This leads to extra gassy and smelly poop.
• Lactose intolerance – An inability to break down the milk sugar lactose leads to gas, diarrhea, and foul-smelling stool. The undigested lactose fuels smelly bacteria production.
• Celiac disease – When gluten damages the small intestine, malabsorption can result. Nutrients end up fermenting in the colon, feeding bacteria and enhancing odor.
• Pancreatic insufficiency – Insufficient digestive enzymes lead to improper breakdown of food, which can fuel odor-causing fermentation and bacteria imbalance in the colon.
• Malabsorption – Problems absorbing fats, lactose, and other nutrients due to conditions like Crohn’s, celiac disease, and cystic fibrosis allow more nutrients to reach the colon and enhance poop smell.
• Food intolerance – Difficulty digesting certain foods like lactose, fructose, or sorbitol can lead to gas, loose stools, and stinky poop. The undigested foods promote gut bacteria growth.
• Gut microbiome imbalance – Too many bad bacteria like Clostridia species or various pathogens can upset your gut balance and cause smelly poop. Antibiotics that kill off good bacteria may also contribute.
• Fistula – Abnormal openings between organs can allow smelly gas or infectious fluid to leak into places it shouldn’t and come out in poop. Fistulas associated with Crohn’s disease are a prime example.
• Blockage – Bowel obstructions in the intestines prevent proper transport of stool. Bacteria go wild in the stagnant poop, emitting very foul odors.
• Colon cancer – Tumors in the colon disrupt the colon environment and normal bacterial activity, sometimes generating horrible smelling stool.
• Cystic fibrosis – Thick intestinal mucus and inadequate nutrition in cystic fibrosis provide an ideal environment for odor-causing, sulfide-producing bacteria.
• C. diff infection – Clostridium difficile bacteria release gases that make poop unbearably stinky. It usually occurs after antibiotic treatment kills off competing bacteria.
• Giardia – This parasitic infection can cause fouls-smelling poop with a distinctive rotten or sulfurous smell. It alters digestion and gut microbial communities.
• Food poisoning – Pathogens like Salmonella and E. coli wreak havoc on your intestinal environment, often leading to incredibly smelly diarrhea. Toxins may also be present.

As you can see, many conditions that affect your gastrointestinal system and gut microbial inhabitants can cause poop smell to take a turn for the worse. But in some cases, fixing your diet is all it takes to get back on track.

What You Can Do

If your poop smells worse than normal, take note of any dietary changes or other gastrointestinal symptoms you’re experiencing. Make an appointment with your doctor if you’re concerned or the smell persists. They can help diagnose potential causes.

In the meantime, try adjusting your diet by:

• Avoiding foods that seem to make the smell worse
• Cutting back on high-protein animal products, dairy, and cruciferous vegetables
• Limiting excess sugar, alcohol, and processed foods
• Staying hydrated to promote regular bowel movements
• Adding probiotics like yogurt or kefir to support gut bacterial balance

Maintaining good hygiene is also important. Be sure to wipe thoroughly after using the toilet. Consider taking activated charcoal supplements to reduce excessive gas. And remember – poop smells. So don’t stress too much if yours has occasional odors. But significant, persistent changes in smell warrant checking with a doctor.

The Bottom Line

A wide range of digestive problems, infections, and dietary factors can cause your poop to smell terrible. Understanding the potential reasons can help you pinpoint sources of the problem. Start by evaluating any diet changes.

See a gastroenterologist if significant smell changes, diarrhea, constipation, or other troubling symptoms occur, to get an accurate diagnosis and proper treatment. With the right adjustments, you can get your poop back to its regular stench in no time.