Aetiology

IBD Curriculum Topic 1.1, 1.4

UC, like CD, is caused by (largely unknown) environmental factors in a genetically susceptible individual. Of the 163 confirmed IBD genes, 110 loci are associated with both UC and CD; only 23 are UC-specific. Therefore it is not surprising that a family history of IBD increases the risk of developing UC although the life time risk of UC in a 1st degree relative is only 2%. Pathways and gene regions of particular importance in UC are the HLA region, IL23R gene on chromosome 1, DLG5 gene on chromosome 10, the JAK/STAT pathway, MDR-1 gene and TLR genes.

Similarly, pouchitis is thought to occur due to interactions between a host’s immune system and pouch microbiota.

The environmental factors predisposing to UC are similar to CD. They include family history of IBD, infectious gastroenteritis, childhood use of antibiotics, and possibly NSAID use. Prior appendicectomy and tobacco smoking may reduce the chance of susceptible individuals developing UC.

ECCO statement 3B (UC 2017)

A family history of ulcerative colitis or Crohn’s disease increases the risk for developing ulcerative colitis [EL2]. Appendicectomy for proven appendicitis before adulthood, and smoking, reduce the risk and severity of UC [EL3]. Smoking cessation may predispose to ulcerative colitis [EL3]

Terms and conditions

By using this site you acknowledge that the content of this website is based on a review process of the ECCO Consensus Guidelines and primarily aims at facilitating their visualization.

Any treatment decisions are a matter for individual clinicians and may not be based primarily on the e-Guide content.

The European Crohn's and Colitis Organisation and/or any of its staff members and/or any website contributor may not be held liable for any information published in good faith on this website.

You agree that the use of this website is at your own risk and hereby waive any and all potential claims against European Crohn's and Colitis Organisation, and/or any of its staff members and/or any of the website contributors.