What is inflammatory bowel disease?
IBD is a group of conditions involving chronic inflammation in the digestive tract. Crohn's disease and ulcerative colitis are the two main forms. Read the IBD introduction.
Crohn's and colitis are different
Crohn's disease can affect different parts of the digestive tract. Ulcerative colitis affects the inner lining of the large intestine. Their symptoms may overlap, but evaluation and treatment are individual.
IBD is not the same as IBS
Similar abbreviations can be confusing. Irritable bowel syndrome and inflammatory bowel disease are different conditions. A symptom checklist alone cannot reliably distinguish them. Compare IBD and IBS.
How common is IBD in the United States?
A CDC/NCHS report published in August 2026 estimated that 1.6% of U.S. adults, about 4.1 million people, had ever received an IBD diagnosis. The estimate used 2023 and 2024 National Health Interview Survey responses from adults aged 18 and older. It describes reported diagnosis history, not the number of people having active symptoms today.
Read the CDC report and its methods. Estimates from different studies can differ because the populations, years and methods differ.
How should you read IBD statistics?
A number needs a population, a date, and a method. Prevalence describes how many people have a condition in a population; incidence counts new cases during a time period. A survey estimate for adults in one country is not the same as a worldwide count of adults and children.
Before sharing a statistic, ask: Which condition does it include? Which country and age range? When was the data collected? Was diagnosis self-reported or measured another way? Different estimates may answer different questions.
Your experience is not an average
Statistics can explain patterns across a population. They cannot predict your individual course, treatment response, or needs. Bring questions about your own symptoms, monitoring and treatment to your care team.