The two major types of inflammatory bowel disease (IBD) are ulcerative colitis and Crohn's disease. Both are characterised by a relapsing and remitting course. In ulcerative colitis the mucosal inflammation affects the rectum and to a variable extent the areas proximal to the rectum in a continuous pattern. Crohn's disease is characterised by discontinuous areas of transmural inflammation that can affect any part of the GI tract but most frequently involves the distal small intestine and proximal colon. IBD has a prevalence of around 400 per 100,000 in the UK. There is a bimodal age of presentation with an initial peak in the second and third decades of life followed by another peak in the sixth decade. Acute ulcerative colitis typically presents with bloody diarrhoea with the passage of mucus, urgency and cramping abdominal pain. A severe attack is usually considered to be associated with bloody stools six times a day or more plus one of the features of systemic toxicity. Severe attacks require intensive inpatient treatment. Inflammatory markers in the blood are not always raised in ulcerative colitis. The diagnosis is confirmed by typical histological features on biopsy. Crohn's disease presents with a typical combination of abdominal pain, diarrhoea and weight loss. Pain or fever may also signify the development of an abscess and stricture formation will lead to obstructive symptoms. Perianal disease in the form of abscesses or fistulae may affect 35-45% of patients during the course of their disease. Because of the chronic and, at times, debilitating nature of IBD special attention to the psychosocial aspects of the disease is very important.