This presentation reviews the course and outcome of disease in 2657 cases of inflammatory bowel disease (IBD) registered into the OMGE multinational survey and considers whether there are differences between the natural history of IBD observed in this series and that observed in earlier large-scale series. It is concluded that several such differences exist. The current mortality from ulcerative colitis (4% in 10 years) is similar to that from Crohn's disease and quite different from that recorded in earlier series (over 20% in 10 years). This may be because the disease itself has changed (the proportion of patient-years with severe attack has fallen from 14.6% in the 1960s to under 10% in the present series). It may also be because of increasing use of maintenance sulphasalazine (since the attack rate per year is significantly lower than patients on maintenance therapy). Finally, cancer is now equally common in Crohn's disease and ulcerative colitis patients; whilst perforation is more common in Crohn's disease (possibly because ulcerative colitis patients now tend to come to surgery earlier).