Case report

We describe a case of a 29 year old healthcare worker who presented with a diarrhoeal illness of 3 weeks’ duration. This young woman had been passing up to seven loose stools a day with mucus but no blood. Her medical history included symptoms consistent with a diagnosis of irritable bowel syndrome with diarrhoea, but there was no particular family history of gastrointestinal disease. She lived with her partner and 11 year old daughter and worked as a student nurse in an adult mental health unit. She was a former smoker, having stopped five years previously. She had no history of foreign travel or contact with animals.

On examination she was apyrexial, pulse was 88 beats per minute, and blood pressure was 118/82 mm Hg. She was diffusely tender over the lower abdomen but had no signs of peritonism. Blood tests revealed a haemoglobin concentration of 13.5 g/dl, white cell count of 12.1×10⁹/l, C reactive protein of 86 mg/l, and normal liver and renal biochemistry. Stool was sampled for microbiological investigation, but was negative for Campylobacter, Salmonella, Shigella, Escherichia coli O157, Cryptosporidium, and intestinal parasites. In addition, an enzyme immunoassay test for Clostridium difficile toxin was negative. Plain abdominal x ray images revealed thickened colonic haustra but no mucosal islands, substantial colonic dilation, or free gas.

The patient was treated conservatively with clear oral fluids and analgesia and underwent flexible sigmoidoscopy on her third day of admission. The colon was …