Abstract
Acute radiation gastrointestinal syndrome (GI-ARS) develops when the intestine is rapidly exposed to large doses of ionizing radiation. In humans, GI-ARS occurs at radiation doses of 6 Gy, with doses of ≥10 Gy typically resulting in death within 10 days. This condition can be caused by various factors, including war, terrorism, nuclear power plant accidents, and cancer therapy-associated adverse events. Developing effective approaches for treating GI-ARS requires a comprehensive understanding of the syndrome. This review summarizes the current body of literature that defines GI-ARS as a consequence of intestinal irradiation. It highlights the paradigm shift in understanding which intestinal stem cells contribute to homeostasis, the critical role of vascular injury in the development of GI-ARS, and recent advances in research on crypt-villus regeneration following radiation injury.