ABSTRACT
The small intestine lies between the duodenojejunal flexure and the ileocaecal valve. The small intestine has a rich blood supply, derived from the superior mesenteric artery, while venous drainage is via the portal venous system. The principal function of the small intestine is the digestion of food and absorption of nutrients, water and electrolytes. The small intestine plays an important role in the metabolism of plasma lipoproteins, as it is the main site of synthesis of high-density, low-density and very low-density lipoproteins. The term ‘inflammatory bowel disease’ is reserved for conditions characterised by the presence of idiopathic intestinal inflammation; conditions such as infective or ischaemic enteritis are, by definition, excluded. Infection with Campylobacter jejuni is the most common form of bacterial gastroenteritis in the UK, typically acquired from eating infected poultry. Salmonella are a family of Gram-negative rods that can cause a range of enteric infections.
