Abstract
Background and Clinical Significanc: Congenital duodenal diaphragm (CDD) is a rare congenital condition causing partial or complete obstruction of the duodenum, most frequently located in the second part of the duodenum. It is a rare but important cause of intestinal obstruction in infants and young children. Clinically, it often presents with persistent vomiting and failure to thrive. Diagnosis can be made through abdominal X-ray showing the characteristic "double bubble" sign, upper gastrointestinal (GI) series, or gastroscopy. Case Presentation: A 17-month-old female infant with known psychomotor retardation was admitted for evaluation of inadequate weight gain and intermittent postprandial vomiting, both present since birth. Laboratory investigations, including metabolic and electrolyte panels, were within normal limits. Given the persistent clinical symptoms, an upper gastrointestinal series was performed to assess for possible anatomical abnormalities. Imaging revealed a significant delay in the passage of contrast into the second portion of the duodenum, with marked prestenotic dilatation. Subsequent gastroscopy identified a duodenal diaphragm nearly occluding the duodenal lumen at the same site, impeding the passage of the endoscope. Associated findings included gastritis and the presence of food debris in the stomach and proximal duodenum, indicating impaired gastric emptying. The patient underwent successful surgical management via duodenotomy with resection of the septum. Postoperative recovery was uneventful. Conclusions: In infants or young children with persistent postprandial vomiting and inadequate weight gain, anatomical causes such as duodenal diaphragm/web should be considered in the differential diagnosis. Once identified, treatment should be initiated promptly, either endoscopically or surgically, depending on the severity and anatomical characteristics of the obstruction.