Inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are chronic immune-mediated diseases of unknown etiology with both intestinal and extraintestinal manifestations. The incidence and prevalence of IBD have been reported to be lower in Asia as compared to the Americas and Europe. Recently, the Asia–Pacific Crohn’s and Colitis Epidemiology (ACCESS) study [1] group showed that there is a rising prevalence and incidence trend in the last two decades. The crude annual overall incidence values per 100,000 individuals were 1.37 for IBD in Asia in 2011. In Singapore, the crude annual incidence of IBD was 1.06 per 100,000 persons in 2011–2012, with UC occurring more than CD (0.61 versus 0.4 per 100,000 persons). The ratios of UC to CD were 2.0 in Asia and 0.5 in Australia. Note that complicated CD (stricturing, penetrating, or perianal disease) was more common in Asia than Australia (52% vs 24%; P < 0.001), and that a family history of IBD was less common in Asia (3% vs 17%; P < 0.001) [1].

Endoscopy serves a number of functions in the management of IBD including diagnosis, monitoring of treatment response, surveillance, and treatment of complications. This chapter provides a snapshot of the current care of patients with IBD, with a focus on the utility of endoscopy in Singapore.

The prevalence of tuberculosis (TB) is high in Singapore, similar to many other Asian countries. Therefore, differentiating IBD from intestinal tuberculosis is critical in the management of IBD. This is in concert with the Asia Pacific Consensus Statements on Crohn’s Disease [2]. According to the World Health Organization (WHO), there were an estimated nine million people who developed TB in 2013, of whom more than half (56%) were in the South-East Asia and Western Pacific Regions [3]. India and China alone accounted for 24% and 11% of total cases respectively. In Singapore, the incidence rate of TB was 37.6 per 100,000 population in 2013 [4], showing a slight decrease compared with the incidence rate between 2009 and 2012, which stagnated at 38.6–40.9 per 100,000 population. There were a total of 2,962 cases of TB notified in 2013. This comprised 1420 new and 119 relapsed cases among Singapore residents (citizens and permanent residents), and 1,381 new and 42 relapsed cases among non-residents (long- and short-term pass holders). The majority (86.3%) of cases had pulmonary TB with or without extra-pulmonary involvement, while the remainder (13.7%) had exclusively extrapulmonary TB. The incidence of gastrointestinal TB in Singapore is similar to other published reports. In a retrospective review of 57 patients who were diagnosed with abdominal TB in a Singapore hospital between 2001 and 2007, the ileum was the most common region affected [5].

There is a close resemblance in the clinical, radiological, endoscopic, surgical, and histological features of CD and gastrointestinal TB. On endoscopy, gastrointestinal TB can present with segmental ulcers and colitis, inflammatory strictures, or hypertrophic lesions resembling polyps and masses. canon rare occasions it presents as pancolitis indistinguishable from ulcerative colitis. A Korean prospective study [6] found that intestinal TB usually has less than four segments involved, a patulous ileocecal valve, transverse ulcers, and more scars. In contrast, anorectal involvement, longitudinal ulcers, aphthous ulcers and a cobblestone appearance were all significantly more common in patients with CD than in patients with gastrointestinal TB. A new endoscopic scoring system to differentiate between CD and intestinal TB has been proposed by the authors, with a positive predictive value for CD of 95% and 89% for tuberculosis. However, it has not been validated for routine use.