inflammation and ulceration of the gastrointestinal mucosa as a result of radiation treatment. The phenotype is radiation-induced gastrointestinal mucositis (EFO_1001914, an Experimental Factor Ontology entry). Also known as: gastrointestinal radiation injury, intestinal radiation-induced injury, ionising radiation-induced duodenal injury, ionising-radiation-induced gastrointestinal syndrome, ionizing-radiation-induced gastrointestinal syndrome, radiation-induced GI syndrome, radiation-induced GI syndrome (RIGS), radiation-induced acute gastrointestinal syndrome.