AbstractToxic dilatation of the colon may be due to inflammatory bowel disease, either ulcerative colitis or Crohn's disease of the colon, but recent experience has shown that infective colitis due to salmonella can produce this complication. We present 13 cases with toxic dilatation (9 inflammatory bowel disease and 4 salmonellosis) and outline the diagnostic features and treatment in these patients. It is important to distinguish salmonellosis at an early stage because, whilst toxic dilatation in inflammatory bowel disease is an absolute indication for surgical treatment, cases with this complication due to salmonellosis may be treated conservatively in the majority of instances.