Antibiotics for inflammatory bowel disease: do they work?

A growing amount of evidence indicates that the intestinal flora plays a pathogenic role in inflammatory bowel disease (IBD): hence, the use of anti-bacterial agents as ancillary treatment in patients with ulcerative colitis, or Crohn's disease. While the results with anti-tubercular agents remain inconclusive, antibiotic treatment in IBD is usually carried out with either metronidazole or ciprofloxacin, or both. Controlled trials are scarce and, although both antibiotics appear to provide clinical benefit, definitive conclusions cannot be drawn and precise therapeutic guidelines cannot be suggested. The best results are achieved in the long-term treatment of Crohn's disease and in the management of pouchitis, or of perianal Crohn's disease. Long-term tolerability of antibiotic treatment may be poor due to the appearance of systemic side-effects. The use of non-absorbable anti-bacterial agents such as rifaximin deserves further investigation.