Gastrointestinal Problems in Athletes

Gastrointestinal symptoms are among the most common causes of underperformance in endurance sport, ranging from reflux, nausea and vomiting to cramps, urgency and diarrhoea.

The causes are multifactorial: reduced gut blood flow (splanchnic hypoperfusion) matters most during prolonged, intense exercise and in the heat, alongside mechanical and nutritional factors and the use of non-steroidal anti-inflammatory drugs (NSAIDs).

For the sport and exercise medicine (SEM) clinician, the work is reducing symptoms with targeted nutrition and gut training, managing reflux sensibly, and investigating gastrointestinal bleeding and iron deficiency rather than assuming exercise is the cause.