Introduction Treatment possibilities have changed in inflammatory bowel disease (IBD). We assessed changes in medical treatment and surgery over time and impact of medications on risk of surgery in a population-based cohort. Methods 48 967 individuals were diagnosed with IBD (Crohn's disease (CD), 13 185; ulcerative colitis (UC), 35 782) during 1979–2011. Cumulative probability of receiving 5-aminosalicylic acids (5-ASA), topical, oral corticosteroids, thiopurines, and tumour necrosis factor-α (TNF-α) blockers, and of first minor or major surgery according to period of diagnosis, was estimated. Medication use and risk of surgery was examined by Cox regression. Results 5-year cumulative probability of first major surgery decreased from 44.7% in cohort (1979–1986) to 19.6% in cohort (2003–2011) (p < 0.001) for CD, and from 11.7% in cohort (1979–1986) to 7.5% in cohort (2003–2011) (p < 0.001) for UC. Minor surgery risk decreased significantly in CD. From cohort (1995–2002) to cohort (2003–2011), a significant increase in use of thiopurines and TNF-α blockers was observed, paralleled by a significant decrease in use of 5-ASA and corticosteroids. Comparing use of azathioprine (or oral corticosteroids) to never-use, no convincing surgery-sparing effect was found. Comparing use in 3+ months of a given drug with use <3 months, only 3+ months use of oral corticosteroids reduced the risk of surgery in patients with disease duration of >1 year. Conclusions Parallel to an increasing use of thiopurines and TNF-α blockers in IBD over time, a persistent significant decrease in surgery rates was observed along with a significant decrease in use of 5-ASA and corticosteroids. However, no convincing surgery-sparing effect of newer medications was found.

BMI was found to be associated with several Ads. This was most pronounced between obesity and risk of sarcoidosis and and risk of type 1 diabetes mellitus. These novel findings need confirmation and the possible role of adipose tissue-derived immunological changes in the development of autoimmune reactions needs consideration.

In this Danish nationwide study, exposure to TNF-α antagonists among patients with IBD was not associated with an increased risk of cancer over a median follow-up of 3.7 years among those exposed. An increased risk associated with longer-term accumulated doses and follow-up cannot be excluded.

UC and CD are dynamic diseases that progress in extent and behavior over time. The resection rate in CD and the colectomy rate in UC are still relatively high, although the rates seem to have decreased compared with historic data, which could be due to an increase in the use of immunomodulating therapy.

ObjeCtiveTo investigate whether people with inflammatory bowel disease treated with tumour necrosis factor-α (TNF-α) inhibitors are at increased risk of serious infections. DesignNationwide register based propensity score matched cohort study.