Gastroenterologists are pausing to reflect on the risks of immunomodulation and reassess the benefits of biological tratment for inflammatory bowel disease (IBD). This is constructive. Every experienced gastroenterologist can recall a case of disseminated varicella zoster, Pneumocystis spp pneumonia or severe sepsis from an otherwise unheard of opportunistic pathogen in a patient with IBD on immunomodulators that they put down to, well, experience. A near disaster skilfully managed, perhaps, but a catastrophe for the patient—especially if such infection was preventable in the first place. So it is indeed constructive that IBD specialists who have long advocated early or increasing use of immunomodulators are sufficiently confident to appraise the risks of infection inherent to immunosuppression. This is precisely what the European Crohn’s and Colitis Organisation (ECCO) has set out to do with their new Consensus on opportunistic infections in IBD.1 It answers the call for a Consensus made in a review of the prevention and diagnosis of opportunistic infections, published in Gut last year.2 It is aimed at specialist gastroenterologists making the diagnosis of and managing patients with IBD. Although the practical implications of the ECCO Consensus for general gastroenterologists are substantial, they are worth the candle. Vaccination and chemoprevention of infection in healthy visitors to exotic locations is accepted by travellers and the community alike, although the absolute risk of infection is generally very much less than the risk of opportunistic infection faced by patients with IBD taking immunomodulators or biological treatment.

So what is the absolute risk of infection in patients with IBD? Inevitably this is difficult to quantify, since there has been no systematic study. The best data come from the carefully controlled trials of biological treatment. In a recent report on adverse events in the global trials of adalimumab for rheumatoid arthritis (RA) and Crohn’s …