Intussusception is a frequent cause of small bowel obstruction in infants and toddlers. Early confirmation and treatment are paramount. We have recognized a fairly consistent radiological finding in plain abdominal x-rays that had not been described previously. The study compares the x-ray findings of patients with proven intussusception with those of patients with colicky abdominal pain related to other causes. In association with the relevant symptoms, this "interrupted air column" in the large bowel should alert one to the possibility of intussusception.