We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Is Runner's Diarrhea?

By Britt Archer
Updated May 17, 2024
Our promise to you
WiseGeek is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WiseGeek, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Many runners, especially those who participate in marathons, suffer from runner’s diarrhea. The condition, also known as "runner’s trots," causes loose stools and makes a runner feel a desperate need to defecate, either during the run or just after. One estimate says the uncomfortable and embarrassing condition affects up to 50 percent of runners. Experts are uncertain of the cause, but advice is available concerning runner’s diarrhea prevention and ways to lessen incidences and keep a runner on course rather than in the bathroom.

Much of the advice concerns changes to a runner’s diet. Foods that are high in fiber should be avoided for 24 hours before a scheduled run, as should foods that cause gas. Another possible culprit that should be avoided are sugar alcohols, a kind of sweetener contained in sugar-free food products, such as ice cream, candy, and some sugar-free gums. Some experts suggest a runner should also avoid fatty foods and caffeine for about three hours preceding a race, and some runners may find they need to avoid these substances for as many as six hours. It is also advisable to completely refrain from eating for a couple of hours before a run.

Advice for runners who are trying to avoid runner’s diarrhea also includes taking precautions with lactose products, such as milk and milk products, because in certain people, lactose can cause diarrhea. Runners also should be aware that energy bars could lead to diarrhea, as can dehydration. Drinking fluids is important, but a runner should pass up any warm drinks, which can accelerate digestion.

Runners who fear a recurrence of runner’s diarrhea might want to take extra precautions with the fit of their clothing because clothing that is too tight can exacerbate the problem. Another safeguard would be to limit the length of the run until improvement is seen. If the problem continues, a visit to a physician may be in order to obtain an antidiarrheal medication. Some runners simply make sure they know the location of restrooms along their route before starting out.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Discussion Comments

By turquoise — On Aug 22, 2014

I think this only occurs during or after long distance running. Those who go for a half hour or one hour job probably won't experience it. I've never experienced. My brother does long distance running and it does happen to him. When he gets back from the run, he has to make frequent trips to the bathroom for a while. Thankfully it hasn't happened to him during a run because I heard that it can be uncontrollable sometimes.

By SarahGen — On Aug 21, 2014

I think anyone who runs a lot or runs marathons experiences this issue at some point. It's nothing to be embarrassed about.

But yes, there are ways to reduce the risks of it occurring. Avoiding unfamiliar foods is a major point. Sometimes, during marathons, they serve random snacks and drinks for the runners. But some of those can actually trigger and aggravate the problem. As a rule, I don't have anything that I'm not used to having when I'm running.

It's also not a good idea to have a large breakfast or a large cup of coffee in the morning of the run. Coffee especially causes intestinal spasms which leads to frequent visits to the bathroom.

By burcinc — On Aug 21, 2014

I think both running and walking gets the digestive system going. It might have to do with our evolution as humans. When humans were hunters and gatherers, they were waking up in the morning and going out to hunt and gather which involved a lot of running and walking. I think that physical activity signals to our body that it's morning and this somehow speeds up the function of the intestines as well.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.