Abstract
Gastrointestinal symptoms in physically active persons can be caused by gut ischemia, dehydration, the use of tobacco and alcohol, medications, and certain foods and fluids. Exercise may also unmask underlying medical problems, the more serious being inflammatory bowel disease, ulcers, and malignancy. Athletes often ignore or are reluctant to talk about symptoms, so physicians must ask specific questions. Diagnosis requires checking orthostatic blood pressure to detect dehydration and conducting a thorough physical examination. Laboratory tests may include a complete blood count, iron studies, thyroid and occult-blood tests, and stool cultures. Treatment may include simple dietary or exercise modifications or medications. Antidiarrheal medications, however, may cause troublesome central nervous system side effects.