Gastrointestinal symptoms in long-distance runners, cyclists, and triathletes: Prevalence, medication, and etiology

OBJECTIVE: The aim of this study was to determine the prevalence of exercis e-related gastrointestinal (GI) symptoms and the use of medication for thes e symptoms among long-distance runners, cyclists, and triathletes, and to d etermine the relationship of different variables to GI symptoms. METHODS: A mail questionnaire covering the preceding 12 months was sent to 606 well-trained endurance type athletes: 199 runners (114 men and 85 women ), 197 cyclists (98 men and 99 women), and 210 triathletes (110 men and 100 women) and sent back by 93%, 88%, and 71% of these groups, respectively. S ymptoms were evaluated with respect to the upper (nausea, vomiting, belchin g, heartburn, chest pain) or lower part of the GT tract (bloating, GI cramp s, side ache, urge to defecate, defecation, diarrhea). For statistical anal ysis, Mann-Whitney U test, Fisher exact test, or Student t test were used. RESULTS: Runners experienced more lower (prevalence 71%) than upper (36%) G I symptoms during exercise. Cyclists experienced both upper (67%) and lower (64%) symptoms. Triathletes experienced during cycling both upper (52%) an d lower (45%) symptoms, and during running more lower (79%) than upper (54% ) symptoms. Bloating, diarrhea, and flatulence occurred more at rest than d uring exercise among all subjects. In general, exercise-related GI symptoms were significantly related to the occurrence of GI symptoms during nonexer cise periods, age, gender, diet, and years of training. The prevalence of m edication for exercise-related GI symptoms was 5%, 6%, and 3% for runners, cyclists, and triathletes, respectively. CONCLUSIONS: Long-distance running is mainly associated with lower GI sympt oms, whereas cycling is associated with both upper and lower symptoms. Tria thletes confirm this pattern during cycling and running. The prevalence of medication for exercise-related GI symptoms is lower in the Netherlands in comparison with other countries, in which a prevalence of 10-18% was report ed. More research on the possible predisposition of athletes for GI symptom s during exercise is needed. (Am J Gastroenterol 1999;93:1570-1581. (C) 199 9 by Am. Coll. of Gastroenterology).