Abstract Three patients are described who developed a diverticulum about the anastomotic line after successful surgical treatment for neonatal jejunoileal atresia. In 2 patients an oblique end-to-end anastomosis, and in the other an end-to-side anastomosis, had been constructed. Clinical presentation with this complication occurred several years after the original operation. The features were bleeding per rectum, anaemia, and ‘failure to thrive’. All 3 were successfully treated by resection of the segment of bowel containing the diverticulum.