Introduction: Primary sclerosing cholangitis (PSC) is a rare, chronic, and progressive cholestatic disease involving intra- and/or extrahepatic bile ducts. PSC in many patients results in end-stage liver diseases. Nearly 60% of the PSC patients suffer from concomitant inflammatory bowel diseases (IBDs). Classically, IBDs are divided into two principle types: Crohn's disease (CD) and ulcerative colitis (UC). However, with growing knowledge, PSC-associated IBD (PSC-IBD) seems to be a rather distinct entity with specific genetics, clinical, and microbiota characteristics.
Areas covered: In this article, we aim to review the unique characteristics of PSC-IBD from clinical, genetic, and microbiota point of view.
Expert opinion: PSC-IBD's unique characteristics contribute to the notion that it could be a distinct entity. Acknowledgment of PSC-IBD as a novel entity necessitates designing new clinical guidelines for diagnosis and developing novel therapies.
Keywords: PSC associated IBD; PSC-IBD; Primary sclerosing cholangitis; inflammatory bowel diseases.