About 1.6 million Americans have inflammatory bowel disease (IBD).1 This figure includes about 780,000 people with Crohn’s disease and another 907,000 with ulcerative colitis.1 Researchers have estimated that 6 to 15 new cases of Crohn’s disease are diagnosed per 100,000 people each year.2
Who has inflammatory bowel disease?
IBD is more common in adults than in children (Table 1).3 People are most often diagnosed with Crohn’s disease and ulcerative colitis in late adolescence or early adulthood, although the diagnosis can occur at any age.1,4 Population-based studies show that Crohn’s disease is slightly more common in women than men, while ulcerative colitis is slightly more common in men than women.4,5
Table 1. Prevalence of Crohn’s Disease and Ulcerative Colitis by Age
| Age Group |
Crohn’s Disease Cases per 100,000 people |
Ulcerative Colitis Cases per 100,000 people |
| Adults (≥20 years) |
241.3 |
263.0 |
| Children and Adolescents (<20 years) |
57.8 |
33.9 |
From: Kappelman MD, et al. Dig Dis Sci. 2013;58:519-525.
Inflammatory bowel disease is more common in whites than African Americans, Asians, Hispanics, or American Indians (Table 2).6 However, the rate of diagnosis in African American patients is on the rise, approaching the rate in whites.4 Ashkenazi Jews are at higher than average risk of Crohn’s disease.7
Table 2. Prevalence of Inflammatory Bowel Disease by Race/Ethnicity
| Ethnic Group |
Cases per 100,000 adults* |
| White |
324 |
| African American |
239 |
| American Indian |
224 |
| Asian |
162 |
| Hispanic |
147 |
*Includes Crohn’s disease and ulcerative colitis.
From: Betteridge JD, et al. Inflamm Bowel Dis. 2013;19:1421-1417.
Does geography play a role in inflammatory bowel disease?
In general, inflammatory bowel disease seems to be more common in the north than in the south.4 Within the United States, the number of people with IBD is higher in the Northeast and Midwest than in the South or West (Table 3).3 Worldwide, the regions with the most new cases of IBD are North America, northern Europe, and the United Kingdom.4 Cases of IBD are much less common in central Europe, Asia, Africa, and Latin America.4
Table 3. Prevalence of Inflammatory Bowel Disease by Geography
| Region |
Crohn’s Disease Cases per 100,000 adults |
Ulcerative Colitis Cases per 100,000 adults |
| Midwest |
264.0 |
61.4 |
| Northeast |
247.2 |
65.1 |
| West |
219.3 |
43.2 |
| South |
219.2 |
54.1 |
From: Kappelman MD, et al. Dig Dis Sci. 2013;58:519-525.
Inflammatory disease also is more common in industrialized countries than in developing nations.4 There are several possible reasons for this pattern. It could be that health care providers in developing nations do not recognize or diagnose the disease. They may attribute diarrhea to infections or other causes. Or there could be environmental factors [Link to: Causes] that protect people in less developed countries from Crohn’s disease. Similarly, changes in diet and lifestyle as societies become more industrialized may be one cause of IBD.
Is inflammatory bowel disease becoming more common?
Several studies have shown that Crohn’s disease is becoming more common in children and adults in the United States. In 2004-2005, 43 children and 214 adults per 100,000 people had Crohn’s disease and 27 children and 235 adults per 100,000 people had ulcerative colitis. In 2008-2009, these estimates rose to 48 children and 236 adults per 100,000 people for Crohn’s disease and 29 children and 248 adults per 100,000 people for ulcerative colitis.3 Hospitalization due to IBD appears to be increasing, too.8
What are the costs of inflammatory bowel disease to society?
Most cost estimates for IBD date back to 2003 and 2004. Current costs may be higher, due to the availability of new medications and changes in surgical treatment.9
The total cost of Crohn’s disease in the United States is about $3.6 billion each year.9 The average yearly medical expenses per patient is $8,265, with more than one-third of that cost due to medications. Biologic medications generally are the most expensive. Hospitalization accounted for 31.4% of the cost.9 On average, people who have to be hospitalized for Crohn’s disease spend about 5.8 days in the hospital.8 Another estimate shows that there were 84,000 days of hospitalization and 1.3 million outpatient visits due to Crohn’s disease.10
The total cost of ulcerative colitis in the United States is about $2.7 billion each year.9 The average yearly medical expenses per patient is $7,948, with hospitalization accounting for the largest portion (37.6%) of those costs and medications making up 27.5% of the total expenses.9
