Clostridium difficile infection is four times more likely to kill patients with inflammatory bowel disease, suggests research published ahead of print in the journal Gut.
C difficile is an important cause of diarrhoea among inpatients, and the numbers of new cases of the infection have been steadily increasing in recent years.
The findings are based on a representative sample of community hospital admissions in the US for 2003.
The sample covered 994 hospitals in 37 States and included a total of 124,570 patients.
Of these, 44,400 had been admitted with C difficile infection, and 77,366 had been admitted with inflammatory bowel disease (Crohn's disease or ulcerative colitis), or IBD for short.
A further 2,804 had both IBD and C difficile infection.
Those with the infection alone tended to be considerably older, and had an average age of 73. Those with IBD had an average age of 42.
The risk of death was higher among those with C difficile infection alone or in combination with IBD than it was in those with IBD alone.
But patients with both the infection and IBD were four times more likely to die than patients with just IBD or C difficile infection alone, irrespective of age.
Patients with the combination also stayed in hospital three days longer and had higher rates of endoscopy, a procedure in which a long tube with a camera on the end is passed through the gut.
Patients with ulcerative colitis had more severe C difficile infection than those with Crohn's disease and worse outcomes.
The authors conclude that patients with IBD may be particularly susceptible to infection with C difficile.