Clinical History.—A 4-year-old boy was admitted to the hospital with a three-day history of abdominal pain, nausea, and vomiting unassociated with diarrhea. He had a rectal temperature of 39.4 C (103 F). The vomitus was bile-stained but without blood or coffee-ground material. There was no history of exposure to infectious disease and no abdominal trauma. His past health had been good with the exception of intermittent vomiting in infancy attributed to "milk allergy."
Physical Examination.—No abnormal findings were discovered on examination.
Clinical Course and Laboratory Studies.—Results of all laboratory studies were normal. He was given fluids intravenously, and when fluids were attempted orally, vomiting returned. On the third hospital day, an upper-gastrointestinal tract and small bowel study was performed and interpreted as a partial obstruction of the third part of the duodenum. However, results of a second study the following day were entirely normal. A full diet