An uncommon cause of ascites: eosinophilic enterocolitis with serous involvement.

Primary eosinophilic gastrointestinal disorders are rare, characterized by eosinophilic infiltration without a secondary cause. Although esophageal involvement is most common, any part of the gastrointestinal tract can be affected. We present the case of a male with symptoms of abdominal distension, retrosternal heartburn, sporadic vomiting, and diarrhea. The patient exhibited hypereosinophilia and elevated IgE levels. Ultrasound revealed diffuse small bowel wall thickening and moderate ascites; diagnostic paracentesis showed leukocytosis with a predominance of eosinophils. A gastrocolonoscopy revealed macroscopically normal findings, but biopsies from the duodenum, ileum, and colon revealed marked eosinophilia. Additional tests were negative. The patient was diagnosed with eosinophilic enterocolitis and started on corticosteroid treatment, with satisfactory improvement. Two years later, the patient has not shown new manifestations of the disease. Eosinophilic ascites is a typical manifestation when serosal infiltration. This form of involvement is the least common but has a good prognosis, usually responding well to corticosteroids and without subsequent flares.