A Giant Enteric Duplication Cyst Presenting as Mechanical Intestinal Obstruction in a Four-Year-Old Child: A Case Report.

Enteric duplication cysts are rare congenital malformations of the gastrointestinal tract that may present with a broad spectrum of clinical manifestations, ranging from incidental findings to life-threatening complications such as intestinal obstruction, volvulus, perforation, and gastrointestinal bleeding. Due to their nonspecific clinical presentation, preoperative diagnosis remains challenging. We report the case of a four-year-old boy who presented with a three-day history of fever, diarrhea, progressive lethargy, and colicky abdominal pain. Initial clinical assessment suggested acute infectious gastroenteritis with dehydration. Laboratory investigations demonstrated elevated inflammatory markers, while abdominal ultrasonography revealed bowel wall thickening, mesenteric lymphadenopathy, and a cystic lesion associated with dilated bowel loops. Despite conservative treatment with intravenous fluids and symptomatic management, the patient's condition progressively deteriorated. He developed worsening abdominal pain, increasing abdominal distension, impaired passage of stool and flatus, and persistent fever. Repeat imaging demonstrated persistent bowel dilatation and multiple air-fluid levels consistent with mechanical intestinal obstruction. Emergency exploratory laparotomy revealed a large enteric duplication cyst arising from the mesenteric border of the small intestine. Partial small bowel resection and drain placement were performed. This case illustrates the diagnostic challenges posed by enteric duplication cysts presenting with symptoms mimicking acute gastroenteritis. Progressive abdominal distension and failure to improve with conservative treatment should prompt repeated surgical assessment and further imaging to exclude underlying mechanical obstruction.