Eosinophilic gastroenteritis is an uncommon disease with an obscure etiology, although associations with allergy, the idiopathic hypereosinophilic syndrome, and connective tissue disease have been reported. We present the case of a 37-year-old woman with a history of idiopathic thrombocytopenic purpura who presented with refractory nausea, vomiting, and abdominal pain. Imaging studies were significant for bowel wall thickening and ascites, while laboratory studies revealed a positive antinuclear antibody (ANA), a positive anti-double stranded (DS) DNA antibody, low complement, and proteinuria. Exploratory laparotomy with gastric and small bowel biopsies established the diagnosis of eosinophilic gastroenteritis. In addition, the patient met clinical criteria for the diagnosis of systemic lupus erythematosus. Previous studies have described eosinophilic gastroenteritis in patients with scleroderma, polymyositis, or dermatomyositis. This is the first report to our knowledge of an individual with eosinophilic gastroenteritis and systemic lupus erythematosus.