Non-surgical causes of pneumoperitoneum—characteristic ‘Rigler's sign’ in a chest x-ray due to pneumothorax with a diaphragmatic hernia

Rigler's sign is a radiological sign of free intraperitoneal air, generally from a perforated viscus. It is the appearance of air on both sides of the bowel wall due to a large quantity of free air in the abdomen. It is important to be aware of the non-surgical causes of this appearance, one of which we describe here. An 87-year-old man whose only medical history was of a long-standing, seemingly asymptomatic, diaphagramatic hernia (figure 1, preoperative film), underwent a total hip replacement with …