Dreaded Diarrhea: A Stinky Topic

author : Nancy Clark
comments : 2

Some athletes call it runners' trots; others call it diarrhea. Whatever the name, few athletes openly discuss the topic yet many secretly suffer. Here’s some information about this stinky topic that m

by Nancy Clark
The Athlete's Kitchen

Q. Does anyone (besides me) worry about undesired pit stops while exercising?  

A: Yes! Diarrhea is a major concern for many athletes, particularly those in running sports, of whom an estimated 20 to 50 percent suffer from "urgency to defecate." Running jostles the intestines, reduces blood flow to the intestines as the body sends more blood to the exercising muscles, stimulates changes in intestinal hormones that hasten transit time, and alters absorption rate. Becoming dehydrated exacerbates the problem. Add a pre-existing bowel problem, and you are even more likely to be bothered by pit stops as your exercise ramps up.

Q. How often do most athletes have a bowel movement?

A: Some athletes poop once a day, others twice a day, and some once every two or three days. “Normal” is what is normal for your body. You can learn your personal transit time by eating sesame seeds, corn, or beets—foods you can see in feces. Pay attention to how much time passes between intake and output.

Exercise (even weight-lifting) speeds up transit time, especially if you do more exercise than usual. A study with healthy, untrained 60-year-old men indicates their transit time accelerated from an average of 44 hours to 20 hours after they started lifting weights.

Q.  Is my diet causing the problem?

A: Your diet can create the problem, but medical issues such as celiac or irritable bowel syndrome (IBS) can cause chronic loose stools.  Just being female increases the risk of experiencing loose stools, particularly at the time of the menstrual period. Add stress, pre-event jitters, high intensity effort and it's no wonder many athletes become plagued by urgency to defecate, particularly novices whose bodies are yet unaccustomed to the stress of hard exercise.

To figure out if the problem is connected to your diet, keep a food and poop chart. For at least a week, eliminate a suspicious food. Observe any changes in bowel movements. Next, eat a hefty dose of the suspected food; observe changes. For example, if you stop having diarrhea when you cut out popcorn, but have trouble during a long run after having eaten a tub of the stuff, the answer becomes obvious: eat less popcorn.

Q. What are the common dietary triggers?

A: Here are a few that top the list:

  1. Fiber. Triathletes with a high fiber intake reported more GI complaints than those with less fiber. Cut back on high fiber cereals, and if needed, fruits, veggies, whole grains. Reduce your fiber intake for 1 to 3 days prior to competition.

  2. Sorbitol. If you enjoy sugar-free gum, candies, and breath mints that contain sorbitol (a type of sugar), take note: sorbitol triggers diarrhea in some people.

  3. Coffee, tea. Hot fluids can stimulate gastric movement.

  4. Fatty foods, spicy foods, alcohol, high does of Vitamin C.

Q. I’ve heard milk causes diarrhea? 

A: Some athletes have trouble digesting lactose, the sugar that naturally occurs in milk. If you are lactose intolerant, you may experience gas, bloating, and diarrhea. Try switching to lactose-free milk (such as LactAid Milk or soy milk).

Q. Should I go on a gluten-free diet?

A: Gluten, a protein found in wheat, is known to cause diarrhea in people with celiac disease. About 1 in 125 people has celiac (gluten intolerance). First get a medical diagnosis before embarking on this difficult diet. Even if diagnostic tests are negative, some people feel better avoiding gluten. For more information, see www.celiac.org and www.GlutenFreeDiet.ca.

Q. I'm afraid to eat or drink anything during exercise. If I succumb, I inevitably get diarrhea. Suggestions?

A: I suggest you start drinking earlier and stay well hydrated. Intestinal complaints are common in athletes who have lost more than 4% of their body weight in sweat. (That's 6 pounds for a 150-pound athlete.) Becoming dehydrated may have triggered the diarrhea, not the water or sports drink.

Your best bet is to train your body to tolerate fluids. Start with small amounts of water during exercise for a week or two, then transition to diluted sports drinks, and then eventually to full-strength sports drinks. Or have plain water + mints or hard candies.

Q. Can I take some sort of anti-diarrhea medication?

A: When all else fails, consult with your doctor about taking anti-diarrhea medicine, such as Imodium, one hour pre-event. Perhaps that will be your saving grace for special events, but not on a daily basis. Caution: Taking Imodium without diarrhea can leave you constipated.

Q. Any other tips to help manage dreaded diarrhea? 

A: Here are some of my best suggestions for triathletes:

  • If you are a morning runner, drink a warm beverage (tea, coffee, hot water) to stimulate a bowel movement. Allow time to sit on the toilet to do your business prior to exercise.

  • Before you embark on a hard workout, exercise lightly to help stimulate a bowel movement, poop, and then exercise hard.

  • Experiment with training at different times of the day. Perhaps morning exercise, after having had a bowel movement, is preferable to an afternoon workout, at which time the intestinal tract has accumulated daytime food and fluids.

  • Choose more foods that tend to be naturally constipating, such as bananas, white bread/bagels, white rice, and pasta.

  • Exercise with a bathroom near by, such as at a gym.

  • Design your running route to include a bathroom, such as a gas station, fast food restaurant, or a friend's house.

  • Before and during exercise, visualize yourself having no intestinal problems. A positive mindset (as opposed to useless fretting) may help control the problem.

As your body adjusts to exercise, your intestines may resume standard bowel patterns. But not always, as witnessed by the number of experienced runners who carry toilet paper with them while running.

The bottom line: You are not alone with your concerns. Yet, your body is unique and you need to experiment with different food and exercise patterns to find a solution that brings peacefulness to your exercise program.

Nancy Clark, MS, RD, CSSD (Board Certified Specialist in Sports Dietetics) counsels both casual and competitive athletes in her practice at Healthworks, the premier fitness center in Chestnut Hill MA (617-383-6100). Her Sports Nutrition Guidebook and food guides for new runners, marathoners, and soccer players are available at www.nancyclarkrd.com . See also www.sportsnutritionworkshop.com.

Biesiekierski JR, Newnham ED, Irving PM, et al. Gluten Causes Gastrointestinal Symptoms in Subjects Without Celiac Disease: A Double-Blind Randomized Placebo-Controlled Trial. Am J Gastroenterol. 2011 Jan 11. [Epub ahead of print]

Chey WD, Cash BD. Irritable bowel syndrome: update on colonic neuromuscular dysfunction and treatment. Curr Gastroenterol Rep. 2006 Aug;8(4):273-81. Review.

de Oliveira EP, Burini RC. The impact of physical exercise on the gastrointestinal tract. Curr Opin Clin Nutr Metab Care. 2009 Sep;12(5):533-8.


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date: February 16, 2011

Nancy Clark

Nancy Clark, MS, RD, an internationally known sports nutritionist and nutrition author, is a registered dietitian (RD) who specializes in nutrition for exercise, health and the nutritional management of eating disorders.

avatarNancy Clark

Nancy Clark, MS, RD, an internationally known sports nutritionist and nutrition author, is a registered dietitian (RD) who specializes in nutrition for exercise, health and the nutritional management of eating disorders.

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