Ulcerative colitis is a relapsing and remitting disease characterised by acute non-infectious inflammation of the colorectal mucosa. In the United Kingdom the annual incidence is around 7cases per 100 000 population.1 The rectal mucosa is invariably affected. Confluent inflammation and shallow ulceration extend proximally from the anal margin. A patient may have proctitis, left sided colitis (the proximal limit being below the splenic flexure), extensive colitis (involving the transverse colon), or pan colitis. At any point in time, 50% of patients are asymptomatic, 30% have mild symptoms, and 20% have moderate to severe symptoms.2 Many patients have long periods of complete remission, but the cumulative probability of remaining free from relapse at two years is only 20%, decreasing to less than 5% at 10 years.3 Later relapses generally affect the same region of the colon as previous episodes.

Several of the current clinical and therapeutic issues in ulcerative colitis include: (a) medical treatment options for relapse and for maintenance of remission; (b) management of the minority of patients who develop a severe life threatening relapse or chronic unremitting disease; (c) surgical treatment of ulcerative colitis; and (d) long term complications in patients with extensive disease—namely, colonic and biliary cancers and sclerosing cholangitis.