Acute abdominal pain in a child with inflammatory bowel disease

A 10 year old girl with inflammatory bowel disease presented with a two week history of eight to 10 bloody diarrhoeal stools a day, abdominal pain, and lethargy. She had been started on oral prednisolone four days before admission. On admission, her inflammatory markers were raised, with a C reactive protein 312 mg/L (reference value <3; 1 mg/L=9.52 nmol/L), white blood cell count 30×10⁹/L (4-10), albumin 34 g/L (35-45), and haemoglobin 104 g/L (110-160). On examination she was unwell, with a heart rate of 140 beats/min, blood pressure of 100/70 mm Hg, and temperature of 38.2°C. She was cool peripherally, with a capillary refill time of three to four seconds, and her abdomen was soft but generally tender. Her paediatric ulcerative colitis activity index (PUCAI) score was 65 (≥65 defines severe disease). She underwent plain abdominal radiography (fig 1⇓).