A rare birth defect where a ligament (median arcuate) is located too low and compresses an artery (celiac artery). When the artery is compressed, blood flow is affected and abdominal pain and other symptoms may occur. The disorder is most common in thin females. Many people may have the anomaly but only in some cases is the compression severe enough to cause symptoms. See also Celiac artery stenosis from compression by median arcuate ligament of diaphragm