A preterm baby presented on day 5 of life with abdominal distension and bilious vomiting. The abdomen was distended and tender. X-ray abdomen showed dilated bowel loops with pneumatosis intestinalis but no pneumoperitoneum. Twenty-four hours later the abdominal distension increased and abdominal transillumination done at the bed side showed increased transillumination (Fig. 1) as compared to a normal abdomen transillumination (Fig. 2). This suggested a diagnosis of pneumoperitoneum which was confirmed with an X-ray abdomen.

Fig.1 Transillumination of the abdomen showing pneum-operitoneum.

Fig.2 Transillumination of a normal abdomen.

Transillumination is commonly used by neonatolo-gists as an emergency bedside procedure to detect pneumothoraces, especially when urgent needle aspiration is required to decompress a tension pneumothorax or when obtaining X-rays may take time. Abdominal transillumination is a simple bedside tool that can be used to diagnose pneumoperitoneum in neonates. Using this, a quick diagnosis can be made even before the X-ray becomes available. This tool will be especially useful in low resource settings, where X-ray facilities are unavailable or take time to organize and will also avoid the need for repeated radiographs in the diagnosis of perforation in the setting of neonatal necrotising enterocolitis.