Going Out Too Often Can Make Your Poop Smell Worse Than Usual (2023)

This article was medically reviewed by Leila Kia, M.D., a board-certified gastroenterologist and member of the Prevention Medical Review Board.

Chances are, you’ve experienced number two sessions so potent that busting out an air freshener was practically mandatory. Sometimes the culprit is super-obvious—a pint of ice cream here, some spicy street food there. Other times, not so much. And when it seems like your poop has become extra smelly out of nowhere, it’s hard not to freak out and Google, “Why does my poop smell so bad?”

For the record, you’re not the only person who has gone through this and it’s highly unlikely you’ll be the last. But, when your BMs are much stinkier than usual, it’s more than understandable to want answers to your pressing questions. Why do your poops smell so bad? Could something be going on with your health? Should you see a doctor?

There’s actually a lot to cover with this one. Pull up a seat.

What influences how your poop looks and smells?

You’ve been pooping your whole life, but you probably haven’t given too much thought to what makes it look and smell a certain way—until now.

At baseline, the pigment found in bile, which is a fluid your body makes in the liver and is stored in the gall bladder, leads to the general brown color of your poop, says Lori Cogan, D.N.P., assistant professor in the School of Nursing at Rutgers, The State University of New Jersey. “These bile pigments are secreted when you eat and are carried by your digestive tract during food digestion,” she says. “These bile pigments make it all the way out into your stool and are the main source of the color of your brown stool.”

But there are other things that also come into play with your overall poop appearance, says Randy Meisner, M.D., a gastroenterologist at Spectrum Health. “A lot of factors go into the way bowel movements look—what food you’re eating, ingredients in your food, a combination of bacteria, and how much water content is in your stool,” he says. Your overall health plays a role, too. “Different body disorders can turn stool different colors than the typical brown color,” Dr. Meisner says. “Absorption, illness, and medications can cause stool to be a different color. Blood can change the color as well.” Basically, there’s a lot that can lead to the overall appearance of your poop.

As for its odor…it’s normal to have poop that stinks. “Everyone has poop that has a less than lovely, perfume-y odor,” Cogan says. And, like the appearance of your poop, there are several things that go into the way your BMs smell. (More on that in a second.)

“Poop smells because of bacteria and their byproducts of digestion,” says New York City-based gastroenterologist Samantha Nazareth, M.D. “If there’s a divergence in smell (let’s say one occurrence), then it could be from something you ate or drank. But if it’s consistently abnormal (as in, different from what your poop usually smells like), then there may be something else going on.”

How concerned should you be about changes in the way your poop smells?

If you randomly have a super smelly trip to the toilet, but things either end or taper off from there, you really shouldn’t stress it. But, “if your stool has a change and is terribly malodorous, or foul-smelling” and it sticks around, there could be something going on, Cogan says.

There’s a massive range of potential causes, from foods you ate to certain medications you’re taking and even underlying illnesses, Dr. Meisner says. Having really smelly poops shouldn’t cause you to panic. But, if they’re sticking around, they’re definitely worth looking into more.

So, why does my poop smell so bad?

What might be causing that extra-smelly poop of yours? Below are several possible culprits—and exactly what to do about them.

1. You’ve been eating sulfur-rich foods.

Sulfur-rich foods—a la meat, cheese, and cruciferous veggies (Brussels sprouts, broccoli, cauliflower)—are harder to digest than other foods, so your gut has to work overtime to get the job done.

“During this process, more gasses are released—hence the more pungent smell,” says California-based functional medicine physician Yeral Patel, M.D. If your diet is heavy on foods that are high in sulfur, consider either shrinking your servings, or avoid combining several sulfur-rich foods in single meals.

2. A food intolerance could be stirring up trouble.

If you find that certain foods cause foul-smelling gas or loose, smelly poop, you might have an underlying intolerance. “A common one is lactose, but people can also have fructose and other carbohydrate intolerances,” says Dr. Nazareth. “The sugar component of the food item isn’t being broken down by the gut.” (Think of the way something smells if it’s left on the kitchen counter and rots.)

Track your food intake for a week or two, and keep tabs on the meals and snacks that end with dicey trips to the throne.

You might find that certain ingredients play a starring role in your digestive debauchery and may need to be taken off the menu. If the thought of parting with these foods causes you to experience a real-life breakup montage, however, you can always find out from your doctor if certain digestive enzymes can give your gut a hand.

3. You downed one too many cocktails.

The kind of alcohol and how much of it you drink can both affect your poop. Alcohol itself is high in sulfates, which the bugs in your gut convert into stinky sulfide gasses. It also changes how fast your digestion works: “Sometimes, when you’ve consumed too much alcohol, the colon works extra hard to excrete the excess waste, flushing it more quickly through your system,” says Dr. Patel.

The excess alcohol, combined with any undigested waste that exits along with it, is what creates that lovely morning-after stench. Besides drinking less or spreading out your cocktails, make sure to drink a lot of water, as dehydration from boozing it up can also affect the rankness of your poop.

4. …or a pile of junk food.

“Highly processed and sugary foods are all difficult to digest,” says Dr. Patel. “As a result, the digestion process takes longer, food remains in your system longer, and the body produces more gasses.”

Plus, junk food is usually high in fat, and sometimes the body can’t break down and absorb the excess properly, says Dr. Nazareth. The fat then passes through undigested and causes smelly poop. To top it off, processed foods contain quite a few iffy chemicals and additives that can give your digestive system attitude, so best to scale back on your intake as much as possible.

5. It’s a side effect of your medication or supplements.

Many medications are coated with substances, such as sorbitol, that can ferment in your gut, causing digestive drama and—you guessed it—smelly poop. Ditto for vitamins and supplements. Consuming even slightly more than the recommended amount can wreak havoc with the bowels too, says Dr. Patel, so make sure you discuss this with your doctor before taking, and ask whether there are steps you can take to avoid disruptions to your digestion.

6. You’re constipated.

The longer poop takes to mosey its way through your colon, the longer it has to ferment and cause a stink. For situational constipation (say, due to traveling or not sleeping), try increasing your water intake and eating easily-digestible foods (baby food consistency), suggests Dr. Nazareth. “There are also stool softeners, fiber supplements, and OTC laxatives,” she adds. But if you’re still backed up and are depending on these OTCs to go to the bathroom, it’s time to check in with your doctor for a consult.

7. A recent switch in your diet could be to blame.

For people on a high-protein or high-fat diet where a lot of meats and cheeses are consumed, the smell of your poop will inevitably intensify. “Most people are used to getting fiber by way of the carbs in their diet, but when those are eliminated, many experience constipation,” says Dr. Patel. “Because the body produces more smelly gasses the longer the stool sits without being eliminated, the smell is unusually bad when it finally comes out.” Another side effect of consuming high-fat meats is that the body can’t deal with the excess fat, and smelly, putrid diarrhea results.

To get the number two train back on the rails, try adding high-fiber foods to your diet that are also considered keto-friendly, such as non-starchy veggies, avocados, and nuts (and don’t forget to guzzle more water as you increase your fiber quota to keep things moving.)

8. You have (or had) an infection.

Gut infections can be viral, bacterial, or parasitic in nature, and cause the gastrointestinal tract to become inflamed—symptoms can include abdominal pain, vomiting, and smelly diarrhea. Your doctor can test your poop to determine exactly the type of infection you have and offer up an appropriate treatment option.

But take note: If you’re prescribed antibiotics, this can also result in foul-smelling poop. The medications typically upset the dynamic between the good and bad bacteria in the gut, says Dr. Patel, so make sure to ask for ways to keep your gut flora happy during treatment.

9. Your overall gut health needs work.

The common thread underlying your poop problems is what docs call malabsorption, where the body can’t absorb certain nutrients properly (such as carbs, protein, or fats), and cause the undigested nutrients to smell pretty foul on the way out. “Some of the illnesses these symptoms can indicate are celiac disease, pancreatitis, Crohn’s disease, or inflammatory bowel disorder,” says Dr. Patel. “These are all conditions that require a doctor’s care and consultation.”

When to see your doctor about smelly poop

There are a few things you can do before calling your doctor. “If your stool smells, and you aren’t on antibiotics or haven’t suffered from a recent infection, we recommend patients keep a journal to see if you can identify any new or regular foods that may correlate with the odorous stool,” Dr. Meisner says.

If you can’t find a link, he recommends weeding out lactose and sugar substitutes from your diet, since both of these can lead to smelly poop. “If after two to three weeks, if you can’t identify or eliminate any foods and are still experiencing odorous bowl movements, it’s time to seek care,” he says.

You’ll definitely want to do that sooner if you happen to have any “red flag” symptoms, he says, including weight loss, abdominal pain, night sweats, or bleeding. “Those aren’t normal and you should seek care immediately,” Dr. Meisner says.