The authors present a case of massive, nonocclusive intestinal ischemia and necrosis after surgery for correction of interatrial communication with cardiopulmonary bypass in a 22-year-old woman. This is an extremely serious complication that generally occurs in older patients. The literature mentions its occurrence in patients subjected to aortic valve replacement who have low cardiac output and in patients undergoing myocardial revascularization. Its occurrence in a young person with simple congenital cardiopathy is rare.