• Liver transplantation
• primary sclerosing cholangitis
• ulcerative colitis

Primary sclerosing cholangitis (PSC) is a rare chronic cholestatic disease of unknown aetiology affecting the biliary tree. It is characterised by bile duct inflammation and fibrosis, and in many patients it progresses to biliary cirrhosis and hepatic failure necessitating liver transplantation. A unique feature of PSC is its strong association with inflammatory bowel disease (IBD). In fact, at least 70% of patients with PSC also suffer from IBD, most commonly ulcerative colitis (UC). Conversely, only 2.5–7.5% of patients with IBD will develop PSC. Although this association has been known since 1965,1 the underlying pathophysiology is still unknown. Despite this lack of fundamental information, hepatologists in clinical day-to-day business often note that patients with PSC are seldom troubled by severe UC. Are these just individual observations or does a common scheme exist?

Surprisingly, there are only a few studies addressing this issue. Patients with PSC with IBD seem to have a higher prevalence of pancolitis with rectal sparing and back-wash ileitis.2 In this study, a lower rate of colectomies was noted in patients with PSC/UC as compared with patients with UC, suggesting a milder course of colitis in the PSC/UC group. Indeed, UC may have a long subclinical course in patients with PSC, as shown in a small Swedish cohort.3 …