Very clever. Bravo.
Dr. Edward R. Laskowski of the Mayo Clinic defines runner's diarrhea as frequent loose stools during (these are fun) or after long runs. The trots are most commonly experienced by, of course, marathoners and other longer-distance runners. Dr. Laskowski says, “The cause of runner's diarrhea isn't clear. One theory is that extreme exercise directs blood flow away from the intestines — contributing to diarrhea......”
According to Active.com, 30%-50% of distance runners suffer from exercise-induced “intestinal problems.” 83% of marathoners occasionally or frequently feel the unwanted laxative effect, if you will, while running. Over half of marathoners reported feeling the need to take a bowel movement during a long run—women suffering more than men.
Dieting runners are more likely than non-dieters to report stomach cramps, bloating, diarrhea, and constipation. 12% of runners reported “fecal incontinence” while running. 10% experience rectal bleeding. Active.com writes, “Bowel problems are a concern for many active people. Yet this topic is rarely discussed; few athletes feel comfortable discussing their dilemma with diarrhea.”
OK, so running IS a natural laxative. Now what? The problem might not be preventable, but there are some things you can do to make it better. First, make sure you drink enough water all day, everyday. It's not enough to hydrate the morning of a big run. Second, avoid sugar substitutes or artificial sweeteners and steer clear of high-fiber foods (like cereals).
These can both make your troubles worse. Third, don't eat anything within two hours of a run. Fourth, reduce common gas-causing and stomach-upsetting foods like beans and lactose. Of course, beans and fiber are considered runner's staple items, so this might be challenging. Finally, wear loose-fitting shorts and tops on runs. A tight waistband can enhance that intestinal jostling.