Failed air enema reduction leading to the diagnosis of small-bowel intussusception secondary to Meckel's diverticulum with ectopic gastric mucosa in a 5-month-old infant: A case report.

A 5-month-old infant presented with paroxysmal crying and vomiting for more than 4 h. Ultrasonography confirmed intussusception in the right abdomen, but intraluminal gas limited precise classification. On the assumption of ileocolic intussusception, air enema reduction was attempted but was unsuccessful. Due to the persistence of symptoms, low-dose computed tomography was performed to further characterize the intussusception subtype. The scan demonstrated concentric ring and pseudokidney-like signs within a segment of the ileum, strongly suggesting small-bowel intussusception. Exploratory laparotomy confirmed ileal-ileal intussusception with Meckel's diverticulum as the pathological lead point. Segmental ileal resection with primary anastomosis was performed, and histopathology demonstrated ectopic gastric mucosa within the diverticulum. The infant recovered uneventfully and remained well at short-term follow-up. This case emphasizes that failed air enema reduction together with indeterminate ultrasonographic subtyping should raise suspicion for a pathological lead point and that low-dose computed tomography should be reserved as a selective diagnostic tool rather than as a routine step in infants with intussusception.