Introduction The incidence of UC in Cardiff has been reported previously between 1968–87. 1 ,2 The incidence of ulcerative colitis is generally regarded as having changed little for some time although some studies have reported increases and reductions over time.

Methods To report the incidence of UC and indeterminate colitis (IC) in Cardiff between 1988–2007.

Pathology database was searched for patients with UC and IC using the following SNOMED codes: colon, inflammation and UC. The patients were included in the incidence study if there was definite histological diagnosis of UC along with corroborative endoscopic findings as described by Lennard-Jones3 and were Cardiff residents at diagnosis (1988–2007). Patients were categorised as IC if they had features of IBD but no definitive diagnosis of either UC or CD on histology.

Results 8340 pathology reports were reviewed and 453 UC and 51 IC patients were identified between 1988–2007. Incidence rates were age and sex corrected to England and Wales population of 2001. Population of Cardiff was 293 600 in 1991 and 305 353 in 2001. 206 UC cases identified in 1988–1997 (corrected incidence=7.01 cases/100 000, 95% CI 6 to 8) and 247 cases between 1998–2007 (corrected incidence=7.96 cases/ 100 000, 95% CI 7 to 9). M: F ratio was 1.2:1 and median age at diagnosis was 35.5 (1988–1997) and 34 (1998–2007). Disease distribution at diagnosis was proctitis (35%), distal colitis (38%) and total colitis (27%) in the entire cohort. Percentage of UC patients were smokers at diagnosis. The corrected incidence of IC for 1988–1997 was 0.94 cases/100 000 (95% CI 0.5 to 1.5) and 0.71 cases/100 000 (95% CI 0.5 to 1.5) for 1998–2007. The comparative crude incidence rates for UC for the period 1968–2007 are shown in Abstract 039.

Conclusion This study shows the incidence of UC is rising in Cardiff in parallel with a small increase in Crohns incidence4 and there is a small decrease in IC incidence rate. Also the incidence of Crohns in Cardiff has shown a small increase.