Diverticular disease is common in older adults, while diverticulitis creates a substantial burden of outpatient visits, hospital stays, surgery, and emergency care. The figures below bring together U.S. estimates and study results from different periods, so each statistic is labeled with its measurement period and scope.
Contents
- How common diverticulosis and diverticulitis are
- Care burden by age
- Care patterns by race and sex
- Mortality and years of potential life lost
- Hospital use and costs
- U.S. trends and surgery
- Outcomes after first-ever diverticulitis
How common diverticulosis and diverticulitis are
Diverticulosis refers to pouches in the colon, while diverticulitis describes inflammation or complications involving those pouches. The prevalence figures from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) describe diverticulosis rather than confirmed diverticulitis. They show a strong age pattern: more than 30% of U.S. adults ages 50–59 had diverticulosis, compared with more than 70% of adults older than 80. These are cited prevalence estimates whose measurement year is not specified on the source page. (NIDDK, “Definition & Facts for Diverticular Disease”)
The same NIDDK source says that less than 5% of people with diverticulosis develop diverticulitis, according to its cited estimate. That distinction matters: a large number of people may have diverticulosis without developing the inflammatory condition. NIDDK also estimates that about 200,000 people are hospitalized for diverticulitis in the United States each year; the page does not specify a year for that annual estimate. (NIDDK, “Definition & Facts for Diverticular Disease”)
A newer population-based U.S. cohort provides a separate measure. Among 31,778,290 adults in 26 health systems followed from February 2015 through February 2020, first-ever acute diverticulitis affected 2.9%. This cohort estimate is not interchangeable with the older prevalence estimates because it uses a defined study population, period, and first-ever acute-diverticulitis outcome. (“Epidemiology of Diverticulitis and Prevalence of First-Ever Colorectal Cancer Postdiverticulitis in Adults in the United States”)
Care burden by age
The NIDDK’s Burden of Digestive Diseases in the United States reports a broader diverticular-disease category. Its tables often combine diverticulosis and diverticulitis, so these older utilization figures should not be read as diverticulitis-only counts. For ambulatory care, the 2003–2005 average reported for 2004 shows a steep increase with age:
| Age group | First-listed ambulatory visits | First-listed rate | All-listed ambulatory visits |
|---|---|---|---|
| 15–44 | 280,000 | 222 per 100,000 | 329,000 |
| 45–64 | 622,000 | 879 per 100,000 | 1.239 million |
| 65 and older | 947,000 | 2,607 per 100,000 | 1.686 million |
The rate among adults 65 and older was therefore reported at 2,607 per 100,000, while the corresponding rate among adults ages 15–44 was 222 per 100,000. The table separates first-listed visits, where diverticular disease was the primary listed diagnosis, from all-listed visits, where it appeared anywhere among the diagnoses. (NIDDK, “Chapter 20: Diverticular Disease”)
Hospital discharge counts in 2004 followed the same age gradient. First-listed discharges numbered 39,000 among adults ages 15–44, 101,000 among adults ages 45–64, and 173,000 among adults 65 and older. When all listed diagnoses were counted, the totals were 59,000, 212,000, and 544,000, respectively. The all-listed hospital-discharge rate among adults 65 and older was 1,498 per 100,000. (NIDDK, “Chapter 20: Diverticular Disease”)
These numbers describe healthcare encounters, not the number of unique people. One person can generate multiple visits or appear in more than one category, and the source’s coding category includes diverticulosis and diverticulitis together.
Care patterns by race and sex
The same NIDDK report provides 2004 ambulatory statistics by race and sex, based on the 2003–2005 ambulatory average. White patients accounted for 1.609 million first-listed ambulatory visits for diverticular disease, compared with 143,000 among Black patients. The corresponding first-listed visit rates were 627 per 100,000 for White patients and 481 per 100,000 for Black patients. These counts and rates describe recorded care in the report’s category; they do not by themselves explain differences in disease risk, access, diagnosis, or treatment.
By sex, female patients accounted for 1.284 million first-listed ambulatory visits, while male patients accounted for 580,000. The first-listed ambulatory-visit rate was 785 per 100,000 among female patients and 434 per 100,000 among male patients. The source does not establish that sex alone caused the difference, and the figures should be interpreted within the source’s broader diverticular-disease definition. (NIDDK, “Chapter 20: Diverticular Disease”)
Mortality and years of potential life lost
For 2004, the NIDDK report recorded 39 underlying-cause deaths among people ages 15–44, with a rate of 0.0 per 100,000, and 306 deaths among people ages 45–64, with a rate of 0.4 per 100,000. Among people ages 65 and older, there were 3,027 underlying-cause deaths, with a rate of 8.3 per 100,000. The age gradient reflects the much higher count and rate in the oldest group.
The report also lists underlying-cause years of potential life lost to age 75, reported in thousands: 1,400 among people ages 15–44, 5,100 among those ages 45–64, and 2,100 among those ages 65 and older. Because these are reported in thousands, the entries represent 1.4 million, 5.1 million, and 2.1 million years, respectively, within the report’s presentation. (NIDDK, “Chapter 20: Diverticular Disease”)
Sex-specific mortality figures for 2004 included 2,299 underlying-cause deaths among women, at an age-adjusted rate of 1.2 per 100,000, and 1,073 deaths among men, at an age-adjusted rate of 0.9 per 100,000. The total was 3,372 underlying-cause deaths at an age-adjusted rate of 1.1 per 100,000. The source also reports that underlying-cause mortality declined from 1.64 per 100,000 in 1979 to 1.10 per 100,000 in 2004. (NIDDK, “Chapter 20: Diverticular Disease”)
Hospital use and costs
An Agency for Healthcare Research and Quality Healthcare Cost and Utilization Project Statistical Brief counted 313,500 U.S. hospital stays with a principal diagnosis of diverticulosis and diverticulitis in 2004. The combined category is important: the figure does not isolate diverticulitis from diverticulosis. The mean patient age was 66 years, and these conditions represented about 12% of U.S. gastrointestinal hospitalizations in that year. (AHRQ HCUP, “Statistical Brief #12”)
The mean inpatient stay was 5.2 days. The mean hospital cost was $8,300 per stay in 2004 U.S. dollars, while aggregate hospital costs totaled $2,543,803,000. Emergency departments were the admission source for 65.6% of these stays, indicating that much of the recorded inpatient burden began with emergency evaluation. The in-hospital death rate was 1.0%. (AHRQ HCUP, “Statistical Brief #12”)
These cost figures are historical 2004-dollar estimates, not current prices. They also represent hospital costs and utilization in the combined diagnosis category, so they should not be used as a current estimate of the personal cost of a diverticulitis episode.
U.S. trends and surgery
An inpatient analysis of U.S. data from 1998 through 2005 found that annual age-adjusted acute-diverticulitis admissions increased from 120,500 in 1998 to 151,900 in 2005, an overall increase of 26%. The increase was 82% among patients ages 18–44 and 36% among patients ages 45–74. The analysis included about 267,000 patients admitted with acute diverticulitis. (“Diverticulitis in the United States: 1998–2005”)
| Measure | 1998 | 2005 | Reported change |
|---|---|---|---|
| Annual age-adjusted acute-diverticulitis admissions | 120,500 | 151,900 | 26% increase |
| Annual elective diverticulitis operations | 16,100 | 22,500 | 29% increase |
Elective diverticulitis operations rose from 16,100 in 1998 to 22,500 in 2005, a 29% overall increase. Among people ages 18–44, the rate of elective diverticulitis surgery increased 73%. The surgical portion of the analysis included about 33,500 patients operated on electively for diverticulitis. The study summary associated diverticular disease with more than 1.5 million inpatient days annually. (“Diverticulitis in the United States: 1998–2005”)
These trend results describe the 1998–2005 inpatient analysis. They show how utilization changed during that interval, but they are not a forecast and should not be treated as a current national total.
Outcomes after first-ever diverticulitis
The 26-health-system cohort followed 31,778,290 adults from February 2015 through February 2020 and examined colorectal cancer after first-ever acute diverticulitis. Colorectal cancer within one year occurred in 0.57% of people after first-ever acute diverticulitis, compared with 0.31% among people without diverticulitis. The reported odds ratio was 1.8, with a 95% confidence interval of 1.76–1.86. (“Epidemiology of Diverticulitis and Prevalence of First-Ever Colorectal Cancer Postdiverticulitis in Adults in the United States”)
Among the colorectal cancers diagnosed after diverticulitis in that cohort, 92.3% were diagnosed within the first six months. This timing result applies to the study’s defined population and follow-up window; it does not mean that every person with diverticulitis will develop colorectal cancer, nor does it provide an individualized risk assessment. The study’s results are descriptive statistics from a U.S. administrative or health-system dataset, while the older NIDDK and AHRQ figures use broader combined diverticular-disease categories and earlier periods.
The statistics across these sources therefore answer different questions: prevalence estimates describe how common diverticulosis is, encounter data describe recorded care, hospital studies describe utilization and costs, and the 2015–2020 cohort describes first-ever acute diverticulitis and one-year colorectal-cancer outcomes in a very large U.S. population. These are descriptive statistics, not personal medical advice.