Methods:: A national cohort of prospectively and retrospectively acquired incident cases of PIBD diagnosed less than 16 years old in pediatric services in Scotland was captured for the period 2003–2008; historical Scottish data were used for comparison (1990–1995). Age/sex‐adjusted incidences were calculated and statistical comparisons made using Poisson regression.
Results:: During the 2003–2008 study period 436 patients were diagnosed with PIBD in Scotland, giving an adjusted incidence of 7.82/100,000/year. The incidence of Crohn's disease (CD) was 4.75/100,000/year, ulcerative colitis (UC) 2.06/100,000/year, and inflammatory bowel disease‐unclassified (IBDU) 1.01/100,000/year. Compared with data from 1990–1995 when 260 IBD patients were diagnosed, significant rises in the incidence of IBD (from 4.45/100,000/year, P < 0.0001), CD (from 2.86/100,000/year, P < 0.0001), and UC (from 1.59/100,000/year, P = 0.023) were seen. There was also a significant reduction in the median age at IBD diagnosis from 12.7 years to 11.9 years between the periods (P = 0.003), with a continued male preponderance.
Conclusions:: The number of Scottish children diagnosed with IBD continues to rise, with a statistically significant 76% increase since the mid‐1990s. Furthermore, PIBD is now being diagnosed at a younger age. The reason for this continued rise is not yet clear; however, new hypotheses regarding disease pathogenesis and other population trends may provide further insights in future years.