Solution: Eosinophilic gastroenteritis is characterized by the selective infiltration of eosinophils in the stomach, small intestine, or both. Any layer of the GI tract can be involved. Atopy is present in a subset of patients and the cause is idiopathic. There is a differential in this case, but the normal appearing terminal ileum makes inflammatory bowel disease less likely and the normal vasculature and young age makes ischemia quite unlikely as well. Therefore, the primary consideration is an infectious enteritis, or something a little more unusual like eosinophilic gastroenteritis. Patients with eosinophilic gastroenteritis have elevated IgE and eosinophilia of tissue and blood. Diagnosis is usually made with scoping and biopsy. Treatment is primarily dietary and medical with surgery to be avoided if possible. Since it is to some degree a diagnosis of exclusion, other possibilities also need to be evaluated and ruled out. Truly, this is a differential case, so if you got the diagnosis correct, congratulations.