Common Digestive Diseases in Singapore Presented by: A/Prof HO Khek Yu and A/Prof YEOH Khay Guan Digestive diseases in Singapore, classified by prevalence Common Peptic ulcer Hepatitis B infection Helicobacter pylori infection Acute Hepatitis A Functional GI disorders Liver cirrhosis Colorectal cancer Liver abscess Gastric cancer Gallstones Liver cancer Less Common Inflammatory bowel disease Oesophageal cancer Reflux oesophagitis Hepatitis C infection Gastro-oesophageal reflux disease Chronic pancreatitis Barrett's oesophagus Pancreatic cancer Uncommon Celiac disease Primary biliary cirrhosis Cystic fibrosis Peptic ulcer disease Duodenal and gastric ulcers collectively account for about a quarter of patients with dyspepsia presenting to hospitals for endoscopy. In recent years the impression is that the incidence of ulcer disease is decreasing, due to more effective treatment with modern anti-ulcer drugs as well as treatment of Helicobacter pylori infection. Helicobacter pylori infection The prevalence of H pylori infection increases with age. The prevalence of infection is highest in Indians, followed by Chinese, and lowest in Malays. This ethnic distribution correlates well with that of peptic ulcer disease, which is common in Chinese and Indians but less frequent in Malays. However functional dyspepsia is equally prevalent amongst the three races. Functional GI disorders The community prevalence of irritable bowel syndrome (IBS) is considerably lower locally compared to the West. Yet about half of all patients seen in a gastroenterological clinic have functional disorders. Therefore the latter conditions still account for the majority of patients presenting with GI symptoms. Gastro-oesophageal reflux disease There is strong epidemiological evidence that gastro-oesophageal reflux disease is less common in Singapore than the West. The prevalence of endoscopic oesophagitis, symptomatic gastro-oesophageal reflux in pregnancy and community reflux-type symptoms are all lower among Singaporeans compared to their western counterparts. A community-based survey also revealed that reflux-type symptoms were more common among Indians than Chinese or Malays. Colorectal disease Right-sided diverticular disease is commoner than left-sided involvement locally. Compared to patients with left-sided involvement, patients with right-sided diverticuli are mostly Chinese and tend to be younger. Inflammatory bowel disease is less common than in the West. Its prevalence is higher in Indians than in Chinese and Malays. Gastrointestinal tuberculosis and infective colitis are important differential diagnoses. GI cancers Colorectal cancer is now the most common cancer in Singapore. The incidence among Chinese is approaching that of caucasian populations. Although gastric cancer has declined in incidence over the last three decades, it remains the third commonest cancer affecting men. Despite medical advances, there is little improvement in survival from gastric cancer. Part of the reason is its late presentation. Liver abscess, cholangitis and gallstone disease Liver abscesses are still commonly seen. The great majority of liver abscesses are pyogenic, with Klebsiella species being the commonest organism isolated. Gallstone disease remains common in Singapore. Oriental cholangitis, due to the brown pigment stones, is becoming less frequent than a generation ago. At the same time, there has been an increase in the incidence of western type cholesterol stones. Viral Hepatitis Over the past decade, the incidence of hepatitis A virus infection has been declining, due primarily to improved hygiene and sanitary conditions. Consequently, herd immunity, particularly amongst the young is very low. This may explain why viral hepatitis A is still responsible for about one third of the cases of acute viral hepatitis. Hepatitis B, C and non-A non-B non-C are responsible for the majority of the remaining cases of acute hepatitis. The latter, in particular, has been associated with fulminant hepatic failure. Exposure to hepatitis E has also been reported. Chronic hepatitis B infection is the most common cause of chronic viral liver disease in Singapore. The mode of transmission is from carrier mothers to their children either at birth or shortly after. With the introduction of compulsory vaccination of babies born to carrier mothers, the number of new carriers has reduced in the last decade. Hepatitis B surface mutants may cause breakthrough hepatits B infection despite adequate protection by the available vaccines. Hepatitis B pre-core mutants often cause asymptomatic infection although they can cause severe liver diseases in chronic hepatitis B carriers. Both these variants of the hepatitis B virus have been detected among local hepatitis B carriers. Chronic hepatitis C infection is uncommon. Liver cirrhosis and liver cancer are common diseases and are usually related to chronic hepatitis B infection. Alcoholic and autoimmune liver diseases are less common than in caucasian populations.