What causes colitis?

Updated: Jan 04, 2019
  • Author: David A Piccoli, MD; Chief Editor: Carmen Cuffari, MD  more...
  • Print

Inflammation of the colon can be caused by infection, hypersensitivity to various allergens, ischemia, vasculitis, or several drugs.

The cause of colitis in IBD is unknown, but the available evidence suggests that IBD involves an abnormal immune response, likely to environmental factors, in a genetically susceptible host. The observation that IBD is occurs more frequently in industrialized, as opposed to developing, countries has led to the “hygiene hypothesis.” The hygiene hypothesis suggests that in parts of the world where humans are exposed to fewer microbes, the intestinal immune system might not be as prepared to respond to antigens. Like bacteria, diet is thought to be a potential environmental factor as the bacteria and diet are two of the most common environmental factors to which the gut is exposed.

Evidence also suggests a genetic predisposition to IBD, including ethnic differences, family aggregation, concordance rates in twins, chromosomal linkage, and genetic syndromes associated with IBD. However, the lack of total concordance of disease among monozygotic twins, along with other differences, supports a role for environmental cofactors in the development of IBD.

In the United States, bacterial and viral infections are very common causes of colitis, whereas in developing countries, parasitic infections are very common causes.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!