Irritable Bowel Syndrome and Gastrointestinal Issues in Endurance Athletes

Abstract

Gastrointestinal (GI) issues are known to be common among endurance athletes and can impair performance in training and competition. Symptom characteristics, particularly those of the lower GI, are similar to irritable bowel syndrome (IBS). No previous research has examined IBS diagnosis or fit to IBS diagnostic criteria within this population. PURPOSE: To determine the prevalence of IBS among endurance athletes as well as their GI symptom management strategies. METHODS: A 92-item online questionnaire was previously validated for the purpose of assessing IBS diagnosis, fit to IBS diagnostic criteria (Rome III or Manning), general GI symptoms, and symptom mitigation strategies of endurance athletes. The questionnaire was distributed between December 2015 and October 2016 to the athletes in the U.S. completing a marathon, ultra-marathon, half-distance triathlon, or full-distance triathlon within that calendar year. RESULTS: The total prevalence of irritable bowel syndrome among 321 endurance athletes who completed the questionnaire was between 9.0% to 22.1% (medically diagnosed: 1.6%; undiagnosed but meeting the diagnostic criteria: 7.5% fitting Rome III criteria or 20.6% fitting 3 2 Manning criteria). Significantly more IBS sufferers were undiagnosed (p=.007 or <.001 for Rome III and Manning, respectively). Only 10.9% of athletes reported seeing a medical professional due to GI issues, while 17.1% had issues which sometimes or often interrupted or prevented their training. Additionally, 65.7% experienced at least one lower GI symptom at a frequency of sometimes or more during training. Almost half (46.7%) of the athletes tried nutritional modifications to help ease their symptoms and 19.0% used over-the-counter medications. CONCLUSION: Most endurance athletes that may suffer from IBS are undiagnosed, while even more have GI issues but do not fit IBS diagnostic criteria. The overall prevalence may be greater than that seen in the general population and the percent diagnosed may be lower among endurance athletes. Despite using various methods to manage their symptoms, endurance athletes are still experiencing issues and could potentially benefit from current IBS-mitigating strategies. Supported by University of Illinois Nutritional Science Margin of Excellence Research and Vision 20/20 Awards.