Unravelling the Enigma: A Young Woman With Ascites and Gastric Outlet Obstruction

Eosinophilic gastroenteritis (EGE) is a rare, heterogeneous, immune-mediated disorder characterised by eosinophilic infiltration of the gastrointestinal tract. It is subclassified based on the depth of tissue involvement into mucosal, muscular, and serosal types. We present a highly unusual case of EGE in a previously healthy 23-year-old woman with abdominal pain, ascites, and vomiting. What makes this case exceptionally rare is the simultaneous involvement of all three layers—mucosal, muscular, and serosal—a pattern seldom reported in the literature. Laboratory findings revealed marked peripheral eosinophilia and non-portal ascites. Endoscopic biopsies confirmed dense eosinophilic infiltration in the mucosa and submucosa, whereas cytological analysis of the ascitic fluid supported serosal involvement. The secondary causes of eosinophilia were excluded. The patient responded rapidly to corticosteroid therapy. This case illustrates an extraordinarily rare presentation of EGE and highlights the diagnostic challenges and the need for a comprehensive, multidisciplinary approach when multiple layers of the GI tract are involved.