Eosinophilic gastroenteritis occurs when certain white blood cells known as eosinophils get into the digestive tract and cause damage. Symptoms of Eosinophilic gastroenteritis usually start in adulthood and may include stomach pain, nausea, vomiting, and the inability to absorb nutrients from food. Sometimes, a blockage in the intestines occurs. The exact cause of Eosinophilic gastroenteritis is unknown, but it may be due to an abnormal response of the immune system to food allergies. Diagnosis is based on the symptoms, a clinical exam, laboratory tests, and by excluding other more common conditions.