University of Tsukuba Dec 2 2025 Primary sclerosing cholangitis (PSC) is a chronic, progressive inflammatory disease characterized by fibrosis and bile duct stricturing, which ultimately leads to cirrhosis and liver failure. PSC is strongly associated with both types of inflammatory bowel disease (IBD), namely, ulcerative colitis and Crohn's disease. However, the patient population in Asia is relatively small, and no large-scale studies have previously examined the prevalence and clinical