Type I atresia of the caecum

A neonate presented with a bowel obstruction which was found to be a type I atresia of the caecum. Barium enema showed the “windsock sign” [1]. The distal side of the membrane had colonic mucosa, while the proximal side had small bowel mucosa despite being completely inside the caecum. These findings support the hypothesis of Ein et al. [3] that the membrane is the remnant of an intussusception in utero.