Questionnaire on Irritable Bowel Syndrome and Symptom Management Among Endurance Athletes Is Valid and Reliable

Lauren A. Killian, Karen M. Chapman-Novakofski, Soo-Yeun Lee

Gastrointestinal symptoms are reported in a large proportion of endurance athletes, with similarities in symptom type and distribution to irritable bowel syndrome (IBS). The objective of this study was to develop and validate a questionnaire to assess IBS diagnoses or fit to IBS diagnostic criteria in this population along with nutritional habits, gastrointestinal symptoms, and symptom management strategies. A 93-item Endurance Athlete Questionnaire was developed to address the objective, targeted at American endurance athletes completing a marathon, ultra-marathon, half-distance triathlon, and/or full-distance triathlon that year. Content validity was established by expert reviewers (n = 6), and face validity was evaluated by endurance athletes (n = 9). Test-retest reliability was assessed by target athletes (n = 51). Participants completed two rounds of the questionnaire, separated by 1-2 weeks. Results were analyzed using Pearson and Spearman correlations and paired comparisons. Slight modifications in wording and three demographic questions were added based on the input of expert and athlete reviews. Pearson correlation coefficient of test-retest total questionnaire scores was significant at 0.839 (P < 0.001). Paired comparison of individual questions found significant differences in 10 of 236 analyzed responses; however, these did not affect fit to IBS diagnostic criteria for those without other GI diseases/disorders. The Endurance Athlete Questionnaire proved to be a valid and reliable measure of IBS diagnostic criteria, gastrointestinal symptoms, nutritional habits, and symptom management strategies among endurance athletes. Future implementation will help inform gastroenterologists with endurance athlete patients and can elucidate whether certain behaviors could be contributing to athlete gastrointestinal symptoms.