A 20-year old woman with a long history of abdominal symptoms presented with acute abdominal pain associated with nausea and vomiting. She had had a right iliac fossa end-ileostomy previously fashioned at the age of 11 months for neuronal intestinal dysplasia. A few days after her admission she suffered a hypokalaemic cardiac arrest from which she was resuscitated. Her clinical condition deteriorated as she became increasingly septic. She was diagnosed with a fulminant colitis based on the clinical picture and the finding of fluid filled, thick walled rectum suggestive of proctocolitis on a pelvic magnetic resonance imaging scan. She was taken to the operating theatre where she had a subtotal colectomy. The histopathological diagnosis was that of fulminant diversion colitis. The patient recovered from surgery and was discharged home 5 weeks later.