0.34 A recent JAK inhibitor hospital-based

study in Sri Lanka reported an incidence of UC of 0.6935 and CD of 0.09. In the West, the incidence of CD has overtaken that of UC in a number of studies.8–12 Traditionally in low incidence areas UC emerges first followed by CD, but over time the incidence of CD ultimately matches, and may eventually overtake, the incidence of UC.2,44 A recent review from China compared the crude incidence for CD and UC in the Chinese medical literature over two time periods: 1989 to 2003 and 2004 to 2007. In both periods, there were more cases of UC, but a relative increase in CD was seen, with the UC to CD ratio dropping from 41 to 15 over time.45 Similarly, a study from South Korea has reported a higher incidence of UC than CD, but the rise in incidence of CD between 1986 and 2005 was more rapid than that of UC, with the ratio of the incidence of UC to CD dropping from 6.8 to 2.3 between 1986 learn more and 2005.13 A recent pediatric study from Korea demonstrated that a rising incidence of IBD diagnosis was more marked for CD, with a new patient CD : UC ratio of 3.4 : 1.46 Overall,

incidence rates of IBD in Asia are still low compared to recent figures from Western countries such as North America, Canada, New Zealand and Australia, where incidence rates for CD and UC range from 14.6 to 17.4 and 7.6 to 14.3, respectively.9–12 Prevalence.  A rise in the prevalence of UC in Japan from 7.85 to 63.6 per 100 000 population has been reported across three different studies between 1984 to 2005.14,16,28 Data from the national register have demonstrated the CD prevalence rise from 2.9 to 13.5 between 1986 and 1998.15 A separate study from Japan documented CD prevalence to be 21.2 in 2005.16 In Hong Kong the prevalence of UC appears to have almost tripled from 2.3 to 6.3 over the period 1997 to 2006.25 There are very few reports of prevalence of CD in Hong Kong or China. One review, which extrapolated

the crude prevalence rate based on 55 years of research in China (which included the Chinese literature), calculated the prevalence of CD to be 2.29;27 this figure has increased from the estimate of 1.3 in a hospital based study in 1994.23 There has been a substantial rise in UC prevalence in Korea from 7.6 in MCE公司 1997 to 30.9 in 2005.13,47 In 2005 CD prevalence was reported to be 11.2.13 A selective report in 19-year-old males having a health assessment for military service in Korea identified a striking increase of more than threefold over the period 2006 to 200948 Although no diagnostic criteria were reported, the latter report supports a likely major increase in IBD prevalence in this country over the last one or two decades. In studies from Singapore, UC and CD prevalence has risen from 6.0 to 8.6,31,32and from,1.3 to 7.2,31–33 respectively.