Introduction Eosinophilic gastroenteritis (EGE) is a rare idiopathic disease that can affect one or more organs of the digestive tract. It has an estimated incidence of 1–20 cases per 100,000 patients. Klein et al. classified EGE into 3 subtypes: predominant mucosal, muscular, or subserosal. Clinical Case We report a case of a 32-year-old woman, who presented with diffuse abdominal pain, nausea, postprandial infarction, diarrhea, and moderate ascites of three-week evolution. The rest of physical examination did not show alterations. The past medical history was unremarkable. Laboratory test results revealed peripheral blood eosinophilia. Abdominal CT scan revealed diffuse and concentric parietal thickening of the distal 2/3 of esophagus, moderate volume ascites, and small bowel wall thickening and distension on the left quadrants. The paracentesis revealed 93.3% of eosinophils. The colon biopsies evidenced an increase in the number of eosinophils. Secondary causes of eosinophilia were excluded. The patient was treated with oral prednisolone 40 mg/day with immediate clinical and analytical improvement. Conclusion Eosinophilic gastroenteritis is a rare condition with a nonspecific and highly variable clinical presentation, which requires a high level of clinical suspicion. It is a diagnosis of exclusion. Secondary causes of eosinophilia such as intestinal tuberculosis, parasitosis, and malignant neoplasms should be excluded.