Colonic perforation is an uncommon but severe complication of colonoscopy. We present a case of a 10 -year-old girl who was treated conservatively for inflammatory bowel disease for 6 years. She underwent a diagnostic colonoscopy after which she developed acute respiratory failure. Urgent bedside imaging series revealed pneumothorax, pneumomediastinum and pneumoperitoneum. A chest tube was immediately inserted, and then she was intubated and ventilated. Laparotomy revealed a 1 cm wide perforation of the transverse colon. The rupture was closed and a terminal ileostomy was performed. The postoperative course was uneventful. To best of our knowledge no other case of pneumothorax, pneumomediastinum and pneumoperitoneum after colonoscopy in children has been reported so far in literature.