Exercise-Induced Gastrointestinal Ischemia and Ischemic Colitis in Endurance Athletes: a narrative review

Background. Endurance exercise redistributes cardiac output away from the splanchnic circulation toward working muscle and skin, producing physiological hypoperfusion that in most athletes resolves without consequence but in some progresses to mucosal injury, gastrointestinal bleeding, or ischemic colitis. The spectrum spans transient biomarker elevation to colonic infarction requiring surgery, yet the determinants separating benign hypoperfusion from tissue-damaging ischemia remain incompletely defined.Aim. To synthesize evidence on the pathophysiology, risk factors, presentation, diagnosis, and management of exercise-induced gastrointestinal ischemia and ischemic colitis in endurance athletes, and to critically appraise the strength and consistency of the underlying evidence base.Materials and Methods. This narrative review draws on peer-reviewed epidemiological studies, exercise physiology trials, case series, systematic reviews, biomarker validation studies, and clinical practice guidelines addressing gastrointestinal ischemia in the context of physical exertion.Results. Splanchnic blood flow can fall by 60-80% during strenuous exercise, correlating with intensity and lactate accumulation. This hypoperfusion produces measurable enterocyte injury (elevated intestinal fatty acid-binding protein), increased intestinal permeability, and, in susceptible individuals, ischemic colitis, most commonly affecting colonic watershed zones.Conclusions. Exercise-induced gastrointestinal ischemia exists on a continuum from asymptomatic biomarker changes to life-threatening ischemic colitis. Recognition of risk factors, appropriate pre-race and in-race prevention strategies, and prompt clinical suspicion in athletes presenting with abdominal pain and hematochezia after endurance exercise are essential to reduce morbidity.