Last Updated on June 30, 2023 by Steven Root


In this article, we will review and provide a summary of the study data published in Digestive Diseases & Sciences regarding ulcerative colitis age of onset.

The study is named Association of Age at Diagnosis and Ulcerative Colitis Phenotype and covers the following:

  • The general age of onset of ulcerative colitis
  • How age at diagnosis influences the disease phenotype
  • The impact of age on disease extent and severity
  • The role of race and family history in ulcerative colitis onset

Age of Onset: An Important Factor in Ulcerative Colitis

Ulcerative colitis (UC) primarily affects young adults, but a significant 12% of patients are diagnosed at an advanced age. The age of onset can play an important role in determining the disease phenotype and severity.

Age Groups and Disease Phenotype

The age of diagnosis can be categorized into three groups: under 17 years, between 17 and 40 years, and over 40 years. Each age group presents a unique disease phenotype:

  • Under 17 years: Patients in this group are more likely to have a positive family history of inflammatory bowel disease (IBD). They also tend to have a longer disease duration from the time of diagnosis.
  • Between 17 and 40 years: This is the most common age group for UC diagnosis. The disease duration from the time of diagnosis is shorter than in the under 17 years group.
  • Over 40 years: Patients diagnosed over age 40 are more likely to have extraintestinal manifestations (EIM). They also tend to be former smokers more often than the other age groups.

Age and Disease Extent

Interestingly as the age of diagnosis increases, there is a trend towards a decreased proportion of patients with pancolitis, a form of UC where the entire colon is inflamed:

  • Under 17 years: 80% of patients had pancolitis.
  • Between 17 and 40 years: 66% of patients had pancolitis.
  • Over 40 years: 51% of patients had pancolitis.

After adjusting for sex, race, family history, smoking history, and disease duration, patients diagnosed at age over 40 years were less likely to develop pancolitis compared to patients diagnosed at 40 or younger.

Age of Onset Chart Data for Ulcerative Colitis

The chart represents the percentage of ulcerative colitis patients diagnosed at different age groups.


The age of onset of ulcerative colitis plays a significant role in determining the disease phenotype and extent.

Patients diagnosed at an older age are less likely to develop extensive disease, even after adjusting for factors such as sex, race, family history etc.

This information may be able to guide treatment, and should prompt further investigation into the pathogenesis of UC in different age groups.

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