How To Treat & Prevent Runner’s Diarrhea

runners diarrhea
Fit woman showing hands heart sign on her stomach

Runner’s diarrhea.

Nature’s gift you didn’t ask for.

Few things can ruin a good urn like the fear of pooping your pants during a run.

To shed some light on this crappy situation (pun intended), in today’s post, I’m going to share with you the full guide runners’ diarrhea.

By the end, you’ll learn more about:

  • What is Runner’s Diarrhea
  • The process behind Runners Diarrhea
  • The causes of Runners Diarrhea
  • Foods to avoid when you have runners trots
  • Is your clothing makes you want to poop your pants?
  • What kind of medication works for runner’s diarrhea?
  • Imodium for runners diarrhea? Does it work?
  • And so much more.

Feel excited?

Let’s get started.

Runners’ Diarrhea Explained

Also known as runners colitis or runners trots, runners’ diarrhea refers to gastrointestinal issues occurring during or following a run.

The condition includes a wide range of symptoms: from bloating and nausea to painful cramping, flatulence, and actual loose stools.

For some runners, the urge to defecate might come about mid-run, and for others, it could happen immediately after running as the body is still experiencing the effects of the workout.

You’re Not Alone

Research reports that about y 60 percent of long-distance runners (those who log in 5 miles or more at a given time)  had to take a break during a run for a bowel movement.

Another study published in the British Journal of Sports Medicine claimed that about 30 percent of marathon runners suffer from stomach issues during or after a race.

Symptoms of Runners Diarrhea

Here are the telling signs of runners trots.

These can be experienced during or immediately after a run.

  • Nausea
  • Acid reflux
  • Flatulence
  • Cramping
  • Gas
  • Sudden need to poop

The Causes of Running Induced Diarrhea

So what’s causing you to poop during a run?

The answer remains unclear as it’s likely multi-factorial.

However, there are several theories as to what triggers the runner’s diarrhea.

Let’s explain a few.

The Up & Down Motion

Running’s impact stirs the bowels and jostles the intestines.

This speeds up the flow of food contents, gas, and stool along the digestive tract, causing a sudden need for a bowel movement.

By the way, this is one of the reasons many doctors recommend regular exercise, especially the one focusing on abdominal work to chronically constipated patients.

Limited Blood Flow

Often, running-induced diarrhea is caused by limited intestinal blood flow.

This blood gets diverted away from the intestines, and instead, it’s focused on the legs and other parts of the body.

Our GI tract is sensitive.

Once the blood flow is limited, the intestinal absorption of nutrients and water reabsorption in the colon will turn bad, causing loose stools in the process.

Of course, don’t take my word for it.

Research reports that intense exercise may limit blood circulation to the colon and small bowels by as much as 80 percent.

Bad Food Choices Pre-Run

Diet is often cited as a leading trigger of runners’ diarrhea, especially when consuming high-fat or high-protein meals, especially before a run.


Dehydration not only impacts your performance but your digestive function too.

When you’re in a dehydrated state, your intestine’s ability to absorb content dwindles down.

So they’re left with one and only option: flush out the stomach content.

Other Causes

Many factors may contribute to the onset of diarrhea during or after a workout that could be unrelated to running.

These include:

  • Performance-enhancing drugs,
  • Some prescription medications,
  • Anxiety and stress.
  • Bowel issues like irritable bowel syndrome (IBS),
  • Hormonal changes,

How To Prevent Runner’s Trots

Now that you understand what runners diarrhea is all about, here are some tips for keeping running-induced diarrhea at bay.

You might not like it, but running-induced diarrhea is normal and often not a cause for concern.

Here’s more good news.

There are many things you can do right now to manage your symptoms and prevent runners’ trots in the future.

Eat The Right Things

Some foods fire up the GI tract more than others, speeding up the flow of waste through the intestines.

That’s why you should limit or avoid these triggers three to four hours of a run.

These include:

  • Foods high in fiber, such as veggies, fruits, and whole grains.
  • High-fat foods.
  • Wheat products.
  • Dairy products.
  • Artificial sweeteners.

Don’t Eat and Run

Timing is also important, though there’s no one-size-fits-all rule for it.

As a general guideline, avoid eating an hour or two before a run. Space out your runs and meals longer if you’re prone to runners trots.

Having a meal two to three hours before a run?

Choose simple carbs and check back the list above.

Stay Well Hydrated

As I explained earlier, dehydration can contribute to loose stools while running.

As a general guideline, drink 12 to 16 ounces of water 60 to 90 minutes before a run, giving the excess fluid enough time to pass through.

During long runs, drink eight ounces of water every 15 to 20 minutes.

Just make sure to avoid warm liquids as these may speed up the flow of food through the digestive tract.

What’s more?

Remember to keep track of your hydration levels.

Your pee should be a very light yellow.

If It’s dark, drink up.

Poop Before You Run

In an ideal world, you’d want to run just after taking care of nature business.

That way, you’ll make sure you’re running with an empty GI tract.

If you’re running first thing in the morning, give yourself at least 30 minutes to  “clear the pipes” before heading out.

Or simply plan your route the night before.

Use online maps or an app and choose the route with plenty of rest areas or public toilets.

For most runners, that’s 10 to 15 minutes into a run, or about a mile or so.

You should also be prepared for emergencies.

Carry some spare toilet paper or wet wipes with you in a Ziplock baggie or your pocket just in case.

runners diarrhea

Keep Track

Use a diet journal.

Inside it, keep tabs on everything you eat or drink and when it was ingested.

Then look for patterns that may contribute to the onset of the diarrhea episode mid-run, and assess what you did on the day your stomach misbehaved.

This will not only help you learn more about your unique food sensitivities but also help you find the most efficient ways of fueling your body.

You should also keep track of your bowel movements so you can schedule your runs immediately after your bowel movements.

Wear Loose Clothing

Excessively tight clothing around the waist can constrict blood flow to the intestines, which may make diarrhea worst.

In fact, everything from tight running shorts, compression garments, and running belts can be problematic, especially if you got a lot of content sloshing around your stomach.

This can contribute to making feel you need for a bowel movement or even cause diarrhea (and other stomach issues such as heartburn).

See a Doctor

While runner’s diarrhea is not an exact medical emergency, this is a condition to discuss with your doctor, especially if you experience any of the following:

  • Bloody or jet black stools
  • Intense and frequent diarrhea
  • Appetite changes
  • acute headache that comes on suddenly
  • persistent diarrhea even after the exercise is over
  • Chronic nausea and ongoing abdominal pain.
  • Weight loss

In some cases, you may need medical help in flushing out parasites or bacteria from your body.

You can also be suffering from an underlying medical condition that’s causing your workout trots.

These include:

  • Ulcerative colitis
  • Crohn’s disease
  • Microscopic colitis
  • Celiac disease
  • Irritable bowel syndrome
  • Proctitis

Consulting with your doctor can help you better understand your unique situation.

They might recommend taking diarrhea pills or even undergo a special examination on you such endoscopy if the case seems worst.

Make sure to check if it’s bothering you or last even after your exercise done.

GI problems can recover really well with early treatment.


Runners’ diarrhea is definitely not a welcome guest, whether it’s before, after, or worst of all, during a run.

With a little experimentation and a lot of paying attention to your body, hopefully, you can manage your runner’s diarrhea on your own.

And if things aren’t improving, definitely see a doctor.