This article reviews the literature regarding gastrointestinal disturbances specifically in runners. Upper gastrointestinal problems such as reflux, nausea, vomiting, and gastritis are reviewed. Exercise has been found to alter esophageal motility. These symptoms worsen with increased exertion as well. H(2) blockers have been found helpful for reflux and nausea. The lower intestinal problems of motility and blood loss are discussed. These problems are generally more common and more directly related to running. Also reviewed are endotoxin involvement and transient abdominal pain. Much of the literature deals with marathon and ultramarathon running, showing the extreme effects of running and exertional stress on the body; however, recreational runners may not be so afflicted as these study participants.