How to Avoid Having Diarrhea During Runs

portable toilets at Central Park

Jason Todd / Photodisc / Getty Images

It's not unusual for runners to experience gastrointestinal symptoms including cramps and diarrhea (also known as "runner's trots") during longer runs.

These symptoms are likely the result of blood flow being direct away from the intestines to support active skeletal muscles in the legs and torso. For some athletes, diet can also play a role.

Here are a few tips to help you avoid the runs on your run.

What to Eat (and When)

This issue is more common in novice runners, so it may disappear as you become more fit. Having food in your stomach can also contribute, so try to avoid eating for at least two hours before you exercise.

Choosing Foods

It helps to avoid high-fiber foods like fruit, vegetables, legumes, and whole grains, which empty more slowly from the stomach. Before running, especially long runs, stick to foods that are more binding, such as white rice or bananas.

You might want to consider limiting your intake of milk and dairy products for a day or two before running if you have issues with lactose intolerance. The protein found in dairy products takes a long time to digest.

If you've ever had problems with lactose intolerance or are susceptible to diarrhea, you may want to avoid dairy for the two days leading up to a long run or race.

Staying Hydrated

What you drink matters, too. Coffee and tea contain caffeine, which can increase intestinal contractions, worsen intestinal cramping, and act as a weak diuretic that promotes a need to urinate.

Finally, it is essential for runners to remain well hydrated. While they can be high in sugar, sports drinks like Gatorade and Powerade contain the water and electrolytes necessary to replace what you lose when you sweat as well as the fluid lost if you have diarrhea.

Know Your Bowel Habits

Be aware of your bowel habits and try to time your workouts for after such movement times. If you're running in the morning, give yourself plenty of time to take care of business before you start running.

You should also consider speaking with your doctor about any symptoms that you experience while running. Depending on what you describe, medical testing may be warranted. Your doctor may also be able to recommend additional dietary or drug therapies that may be useful.

Plan Running Routes With Bathrooms

If you're worried that you'll need to use the bathroom at some point on your run, it can be comforting to know where you could potentially make a pit stop.

If you can, plan long runs along routes where you know bathrooms are accessible. It also doesn't hurt to carry some spare toilet paper in your pocket or running belt in case of an emergency.

If you need to make a pit stop on race day, don't worry. You'll find plenty of port-a-johns at the start and along the racecourse. They'll be marked on the course map, and should be easy to spot. In most cases, you'll find them near water stops.

A Word From Verywell

If you've tried many different strategies with no luck, you may want to try an over-the-counter anti-diarrhea product such as Imodium.

While these products are safe to use for exercise-induced diarrhea, you shouldn't make using them a habit. Save them for races or special events where port-a-johns won't be available.

By Christine Luff, ACE-CPT
Christine Many Luff is a personal trainer, fitness nutrition specialist, and Road Runners Club of America Certified Coach.