Series, resources, tools

DefinitionsFor ParentsSeed 101SeedLabs

Coming Soon

Skin Microbiome

Oral Microbiome

Vaginal Microbiome


Your Top Poop Questions, Answered

The one about poop. Here we answer five common questions we receive about bowel movements, from stool smells to why alcohol makes you have to go.

7 minutes

11 Citations

As an organization that is pioneering innovations in gut health and probiotics (among other things), we talk about poop a lot. While the topic can feel taboo and embarrassing, everybody poops. 

No matter how your bowel movements are going—or, more commonly, not going (61% of Americans deal with digestive issues including constipation and irregularity1)—your #2s have a noticeable impact on your life. Stool quality, consistency, and frequency have been linked with various aspects of health, including the composition and richness of your gut microbiome, overall digestive function, and even levels of stress.2,3 

Regardless of how pooping is going for you, everyone can benefit from learning more about this key biological output. The more you know about what’s happening with your stool, and why, the better equipped you’ll be to make decisions to improve its quality and support your overall digestive health. 

Here, SciCare* shares answers to five of the most-asked questions we receive about poop. 

* 👋 SciCare is our team of experts who answer all your science, health, and product-related questions. Have a question? Email

My poop smells. Does this mean my microbiome isn’t doing well? Or the opposite? 

Poop smells are a completely natural part of the business, and research does suggest that your microbes play a role in the scent of your stool.4 How? As food and other inputs like medications and supplements travel through your system, they interact with your resident microbes. Your microbes help break down many of these substances, producing byproducts (metabolites) in the process. Certain smells emitted from stool are due to microbes and the end products of their activity—take, for example, indole. 

A number of bacterial species produce indole when they break down undigested proteins (specifically the amino acid tryptophan) in the colon. Most of what you smell from stool is attributed to indole and its derivatives, including skatole. (Fun fact: In low concentrations, indole compounds actually have a floral scent, and they’re sometimes used in perfumes and can even be added to certain foods.)

Indole is just one compound that contributes to smell, though. Common poop odors can arise from compounds found in sulfur-rich foods such meat, cheese, eggs, onion, garlic, cruciferous veggies (Brussels sprouts, broccoli, and cauliflower), and even wine. Perhaps the most well-known sulfur compound is hydrogen sulfide, which is known for its “rotten egg” smell.  

Given each person’s diet, body, and microbial makeup are unique, poop smells vary from person to person. Plus, on an individual level, the smell of your poop can fluctuate with each new bowel movement, mostly due to shifts in what you consume and the byproducts of its digestion. Because there are many factors involved, poop smells are not necessarily indicative of the quality of your microbiome—though they can clue you in if something is “off” within your gastrointestinal tract as a whole.

While stools normally have an unpleasant odor, a healthy stool should have an odor that is familiar to you. If your stool odor is extremely bad, or abnormal, it could indicate certain digestive conditions like Crohn’s disease, pancreatitis, or lactose intolerance. Though most often, foul-smelling stools that do not persist have more simple causes like a change in diet.

Why do I have to poop when I’m hungover?

DADS (day-after-drinking-sh*ts), booze poos, rum bum—whatever you call it, pooping after drinking alcohol is a very common experience. Why? The short answer is that alcohol is a known gut disrupter. It affects your microbiome, the gut barrier, and your body’s digestive processes, all of which ultimately impact your poop. 

To get more specific, here are a few key ways alcohol impacts your bowel movements: 

1. Alcohol irritates your gut wall.5 The cells that line your intestines are responsible for absorbing nutrients from the food you digest. When your gut wall is irritated, it can temporarily impact your gut’s absorptive capabilities, and what you don’t absorb, you expel.

2. Alcohol acts as a diuretic.6  Alcohol inhibits vasopressin, a hormone that promotes reabsorption of water in the kidneys. That’s why you may urinate more when drinking, and also experience more water in your stool. 

3. Alcohol impacts motility.7 Motility refers to how food and waste moves through your system. Small amounts of alcohol can speed up the rate of digestion, causing diarrhea, while large amounts can actually slow digestion and cause constipation.Fortunately there are some ways to lessen the effects of alcohol on your gut microbiome—you can find five research-informed tips here.

Does DS-01® help you poop? 

We’re glad you asked. Yes, more regular bowel movements is one of the most common effects our members experience when taking DS-01®

That’s because our DS-01® Daily Synbiotic is formulated to support multiple markers of digestive health. For example, our body of research demonstrates that strains in DS-01® promote healthy regularity, support a balanced gut microbiome, and ease of occasional digestive discomforts like constipation and bloating, and support a balanced gut microbiome.

In a double-blind, randomized, placebo-controlled study of the strains L. plantarum LP01, B. breve BR03, and B. lactis HRVD524-US participants who received the probiotic treatment reported a significant improvement in number of weekly bowel movements, consistency of stool, and ease of expulsion.8 Another strain in DS-01®, B. longum BB536, was shown to improve intestinal environment, defecation frequency, and fecal characteristics.9

Further, a 12-week double-blind, randomized, placebo-controlled trial, run at Harvard University, evaluated DS-01®’s effect on individuals with functional digestive issues. DS-01® participants demonstrated a significant improvement in bowel regularity and abdominal discomfort compared to the placebo group.10

All of this translates to easier, healthier, more regular poops.

It looks like there are seeds or grains in my stool. What does this mean?

It can be totally normal to see fragments of undigested food in your stool. Most commonly, the undigested bits are from foods that are high in insoluble fiber​, such as whole wheat flour, wheat bran, nuts, beans, and some vegetables.11 This is because some types of fiber are not fully broken down and absorbed in your digestive tract, so their remnants appear on the other end of it. This is usually no cause for concern, but if you want to manually help your body break these tough inputs down further, you can try chewing your food more thoroughly and eating slowly.

The Corn Test: An At-Home Experiment

Corn is one of the inputs that travels through your digestive system intact. This is because it’s a seed that’s protected by a tough outer shell made of cellulose. Your body doesn’t have the proper enzymes to break down and digest cellulose, so this outer shell passes right through you, and can be seen speckling your poop.

This means you can use corn to measure your transit time—the time from when you initially eat a food to when you poop it out. (Transit time can be an illuminating data point about your digestive health. Learn more.)

Here’s how:

  • Step 1: Swallow 8-15 unpopped corn kernels (no chewing). Log the date and time.
  • Step 2: Check the toilet for kernels each time you poop.
  • Step 3: Once you spot them, note the date and time. 
  • Step 4: Calculate the time passed between Step 1 and 3. That’s your transit time.

Disclaimer: We do not recommend this experiment if you have difficulty swallowing, pre-existing GI conditions, or are allergic/hypersensitive to corn. This experiment is not intended to diagnose any medical conditions nor is it a substitute for professional medical evaluation. If you have any questions or concerns, please consult your primary health care provider. Children should not participate without adult supervision.

I eat a lot of fiber throughout my week, yet I’m still constipated. Is there such a thing as too much fiber? 

If you consume a very high fiber diet, it’s possible you could experience gas, bloating, and constipation—especially if you’ve rapidly increased your fiber intake without giving your body (and your microbes) time to adjust. But how much is too much? Current recommendations for dietary fiber intake for adults in most European countries and in the U.S. are between 30–35 g per day for men and between 25–32 g per day for women. The upper limit to fiber varies with every individual, and there is currently no one established value that’s considered “too much.12” (It’s also worth noting that, for the most part, the greater concern is insufficient intake—it’s estimated that 95% of people do not get enough daily fiber.13)

Aside from how much fiber you’re consuming, the type matters, too, when it comes to your bowel movements. There is variation in the chemical composition, solubility, and size of different dietary fibers, which can influence their function and health benefits within your body. 

Generally fiber is classified into two broad categories: soluble vs. insoluble. Soluble fibers dissolve in water, forming viscous gels. Because of this, they bypass the digestion of the small intestine and are easily fermented by the microbes residing within your large intestine (you can think of them as fuel for your gut microbes). Soluble fibers are derived from the inner flesh of plants—think: apples, barley, carrots, oats, and peas. 

Insoluble fibers, on the other hand, do not dissolve in water. This means they usually cannot undergo fermentation by bacteria in the colon, and instead end up forming the bulk of your stool and promoting laxation. Insoluble fibers are usually derived from the outer skin of plants—beans, nuts, wheat bran, cauliflower, and Brussels sprouts are all good examples.

While most fruit and vegetables contain a combination of both insoluble and soluble fibers, certain foods tend to skew higher in one direction or the other (reference the aforementioned examples). So, if you’re eating foods with a lot of soluble fiber, you could be consuming a high-fiber diet, but you aren’t getting enough insoluble fiber to add bulk to your stool, which can contribute to smaller, less frequent poops. In other words: Pay attention to both the amount and the type of fiber you’re consuming each day.

Of course, fiber is just one of many variables that can influence your bowel movements. If you’re experiencing constipation, it’s also important to consider factors like water intake, physical activity, medication, stress levels, and quality of sleep. And, as always, if you have any concerns, we recommend consulting your doctor, who can help you identify the underlying cause and create a plan of action for treatment. 

We receive and answer questions like these every day. Stay tuned for more SciCare roundups on Cultured. If you have any questions of your own, email us at


  1. Almario, C. V., Ballal, M. L., Chey, W. D., Nordstrom, C., Khanna, D., & Spiegel, B. M. R. (2018). Burden of Gastrointestinal Symptoms in the United States: Results of a Nationally Representative Survey of Over 71,000 Americans. American Journal of Gastroenterology, 113(11) 1701-1710. Doi: 10.1038/s41395-018-0256-8
  2. Vandeputte, D., Falony, G., Vieira-Silva, S., Tito, R. Y., Joossens, M., & Raes, J. (2016). Stool consistency is strongly associated with gut microbiota richness and composition, enterotypes and bacterial growth rates. Gut, 65(1), 57–62.
  3. Mayer E. A. (2000). The neurobiology of stress and gastrointestinal disease. Gut, 47(6), 861–869.
  4. Mogilnicka, I., Bogucki, P., & Ufnal, M. (2020). Microbiota and Malodor-Etiology and Management. International journal of molecular sciences, 21(8), 2886.
  5. Camilleri, M., Lyle, B. J., Madsen, K., Sonnenburg, J. L., Verbeke, K., & Wu, G. D. (2019). Role for diet in normal gut barrier function: developing guidance within the framework of food-labeling regulations. American Journal of Physiology-gastrointestinal and Liver Physiology, 317(1), G17–G39.
  6. Hobson, R. M., & Maughan, R. J. (2010). Hydration status and the diuretic action of a small dose of alcohol. Alcohol and Alcoholism, 45(4), 366–373.
  7. Bujanda L. (2000). The effects of alcohol consumption upon the gastrointestinal tract. The American journal of gastroenterology, 95(12), 3374–3382.
  8. Del Piano, M., Carmagnola, S., Anderloni, A., Andorno, S., Ballarè, M., Balzarini, M., Montino, F., Orsello, M., Pagliarulo, M., Sartori, M., Tari, R., Sforza, F., & Capurso, L. (2010). The use of probiotics in healthy volunteers with evacuation disorders and hard stools: a double-blind, randomized, placebo-controlled study. Journal of clinical gastroenterology, 44 Suppl 1, S30–S34.
  9. Ogata, T., Nakamura, T., Anjitsu, K., Yaeshima, T., Takahashi, S., Fukuwatari, Y., Ishibashi, N., Hayasawa, H., Fujisawa, T., & Iino, H. (1997). Effect of Bifidobacterium longum BB536 Administration on the Intestinal Environment, Defecation Frequency and Fecal Characteristics of Human Volunteers. Bioscience and Microflora, 16(2), 53–58.
  10. (n.d.).
  11. Slavin, J. L. (2013). Fiber and Prebiotics: Mechanisms and health benefits. Nutrients, 5(4), 1417–1435.
  12. Office of Dietary Supplements – Nutrient Recommendations and Databases. (n.d.).
  13. Quagliani, D., & Felt-Gunderson, P. (2016). Closing America’s fiber intake gap. American Journal of Lifestyle Medicine, 11(1), 80–85.