About 4.1 million American adults have been told by a doctor that they have Crohn's disease or ulcerative colitis, according to new federal survey data, and the two conditions are far from evenly split. Ulcerative colitis is more than twice as common as Crohn's.
The estimate comes from the National Center for Health Statistics, using 2023 and 2024 National Health Interview Survey data. It puts overall inflammatory bowel disease at 1.6% of adults, ulcerative colitis at 1.2%, and Crohn's disease at 0.5%.
For anyone living with either condition or waiting on a diagnosis, the most useful part of the report is not the headline total. These are national numbers based on a household survey rather than insurance claims, and they answer a question patients ask constantly: how many other people are dealing with this.
The Split Between the Two Diseases
The report, published as an NCHS Health E-Stat by James M. Dahlhamer and Emily P. Terlizzi, breaks out Crohn's disease and ulcerative colitis separately. That is the part that has been missing from most national estimates.
Ulcerative colitis affects about 3.1 million adults. Crohn's disease affects about 1.3 million people. Because a small number of people report both conditions, the combined figure of 4.1 million is lower than the sum of the two.
That ordering runs against a common assumption. Crohn's disease tends to receive more public attention, partly because it can affect any part of the digestive tract from mouth to anus and produce complications such as fistulas and strictures. Ulcerative colitis, which is confined to the colon, is the more prevalent of the two in this dataset by a wide margin.
The total has also moved. NCHS reports that 1.2% of adults, or about 3.1 million, had an IBD diagnosis in an earlier round of the same survey covering 2015 and 2016, compared with 1.6% now. Whether that reflects genuinely rising disease, better diagnosis, an aging population, or some combination is not something a prevalence snapshot can settle, and the report does not claim to.
Prevalence Climbs Steadily with Age
The clearest pattern in the data is age, and it runs in one direction.
Overall, IBD rises from 0.7% among adults ages 18 to 29 to 2.7% among adults 70 and older. Ulcerative colitis shows the steepest climb, from 0.4% in the youngest group to 2.2% in the oldest. Crohn's disease rises more modestly, from 0.3% to 0.6%. The full data table notes a significant linear trend by age group for all three measures.
That gradient deserves careful reading. The survey question asks whether a person has ever been told by a doctor or other health professional that they had the condition, which makes this a measure of lifetime diagnosis rather than current active disease. Because IBD is lifelong, older age groups accumulate more people who have ever received the diagnosis. The pattern reflects accumulation as much as new onset.
Women were more likely than men to have ulcerative colitis, at 1.4% versus 1.0%, and overall IBD, at 1.7% versus 1.4%. Crohn's disease showed no significant difference by sex.
Prevalence also differed by race and Hispanic origin. White non-Hispanic adults had the highest rates across all three measures, at 0.6% for Crohn's, 1.4% for ulcerative colitis, and 1.9% for IBD overall. Hispanic, Black non-Hispanic, and Asian non-Hispanic adults each had significantly lower reported prevalence across all categories. That gap has appeared consistently in prior research, though this report does not investigate why it exists.
Reading a Survey Estimate Correctly
Several limits are worth stating, because a number this clean can be over-read.
The data come from household interviews and rely on what people report being told by a clinician. No charts were reviewed, and no diagnosis was independently confirmed. The report also notes that its counts may be underestimated because of item nonresponse, and that people whose answers were coded as refused, don't know, or not ascertained were excluded from the calculations entirely.
The survey covers the civilian noninstitutionalized population, so adults in nursing homes and other institutions are not represented.
Prevalence estimates for IBD also vary considerably depending on the data source. CDC's own overview cites a range of 2.4 to 2.8 million patients based on administrative claims data, alongside survey-based figures reaching 3.1 million. Those methods count different things, and a claims-based number and a survey-based number are not interchangeable.
None of this changes clinical guidance for any individual. What the numbers offer is context. About one in 60 American adults has been diagnosed with one of these conditions, which makes IBD common enough that most people know someone living with it, while remaining uncommon enough that primary care clinicians may not see it often.
For readers with persistent symptoms, the practical signal remains unchanged. Diarrhea lasting weeks, blood in the stool, unexplained weight loss, persistent abdominal pain, or nighttime symptoms that wake a person from sleep warrant medical evaluation rather than watchful waiting. Those features help distinguish inflammatory bowel disease from irritable bowel syndrome, which does not cause visible inflammation or tissue damage. Diagnosis generally requires endoscopy and laboratory testing rather than symptoms alone.
Cost and access are real barriers for this population, since IBD treatment often involves biologic medications and specialist care. Patients facing coverage denials can ask their gastroenterology practice about prior authorization appeals, manufacturer assistance programs, and foundation copay support.
NCHS publishes these estimates periodically as new survey years accumulate. Whether the upward movement from 1.2% to 1.6% continues, and whether it reflects incidence or detection, will take further reports to establish.
Key Questions Answered
How many U.S. adults have IBD? About 4.1 million, or 1.6% of adults, have ever been diagnosed with Crohn's disease or ulcerative colitis, according to 2023 and 2024 National Health Interview Survey data.
Which condition is more common? Ulcerative colitis occurs in 1.2% of adults, or about 3.1 million, compared with Crohn's disease at 0.5%, or about 1.3 million.
Does prevalence change with age? Yes. Overall, IBD rises from 0.7% among adults aged 18 to 29 to 2.7% among those aged 70 and older. Because the question asks about lifetime diagnosis, this partly reflects accumulation over a lifetime.
Are women affected more than men? Women reported higher rates of ulcerative colitis and overall IBD. There was no significant difference for Crohn's disease.
Is IBD increasing? The comparable survey figure was 1.2% in 2015 and 2016, compared with 1.6% now. A prevalence snapshot cannot separate rising disease from improved diagnosis.
How reliable are these numbers? They are self-reported diagnoses from household interviews, not verified medical records, and the report notes that counts may be underestimated. Claims-based estimates produce different figures.
When should someone see a doctor? For diarrhea lasting weeks, blood in the stool, unexplained weight loss, persistent abdominal pain, or symptoms that wake them at night.
