Study reveals a troubling surge in severe diverticulitis among Americans younger than 50

A comprehensive analysis of over 5.2 million hospitalizations reveals a troubling surge in severe diverticulitis cases among Americans younger than 50.

The analysis, led by researchers from UCLA and Vanderbilt University and published in the journal Diseases in the Colon & Rectum, reviewed hospital admissions for adult diverticulitis patients in the U.S. from 2005 to 2020. The researchers found that the proportion of younger patients among those admitted with complicated diverticulitis, a subtype of diverticulitis, involving abscesses, perforations or other serious complications increased from 18.5% to 28.2%, a 52% relative increase.

The study’s first author Shineui Kim of UCLA Health and principal investigator Dr. Aimal Khan of Vanderbilt University said the findings point to a growing public health concern for younger Americans, with this population having experienced similar increases in colorectal cancer diagnoses.

“We’re seeing a significant shift in who is being hospitalized for severe diverticulitis,” said Kim, a fourth-year medical student at the David Geffen School of Medicine at UCLA. “This condition was traditionally thought of as a disease of older adults, but our data shows that younger Americans are increasingly affected, and often with more complicated presentations.”

Diverticulitis causes small pouches, or sacs, to form on weak areas on wall of the colon, which can lead to abdominal pain, bloating, bleeding, constipation and diarrhea among other symptoms. The disease has been considered more common among older adults and rare in people under 40.

However, the UCLA analysis of the National Inpatient Sample, the largest publicly available all-payer inpatient healthcare database in the United States, showed a changing trend.

Of the 5.2 million patients hospitalized for diverticulitis between 2005-2020, about 16% or 837,195 were classified as “early-onset” cases occurring in patients younger than 50 years old. Of this early-onset cases, the number of people admitted to the hospital for complicated diverticulitis increased from 18.5% to 28.2%.

Kim said this represents a substantial disease burden in a demographic that has historically been at lower risk.

Despite the increase in complicated cases, treatment strategies have evolved. The proportion of younger patients requiring colectomy to surgically removal of part of the colon decreased from 34.7% to 20.3% during the study period. Kim said this suggests that physicians are successfully managing more cases with conservative approaches.

Kim said the analysis found other differences between younger and older patients with diverticulitis. Compared to older patients, younger patients had:

Lower mortality rates
Shorter hospital stays (0.28 days less on average)
Lower hospitalization costs ($1,900 less per admission)

However, younger patients were more likely to require intervention, with 29% higher odds of needing a colectomy and 58% higher odds of requiring percutaneous drainage, compared to their older counterparts.

While younger patients generally have better survival outcomes and shorter hospitalizations, they’re paradoxically more likely to need invasive interventions. This suggests their disease may be more aggressive or that treatment approaches differ based on patient age and overall health status.”

Shineui Kim of UCLA Health

The researchers said more research into the potential causes of the rising burden of early-onset diverticulitis remain poorly understood. With similar increases seen in this population for colorectal cancer,

“Little is known about why we’re seeing this increase in younger patients,” said Kim. “We urgently need additional research to determine what’s driving these trends whether it’s dietary factors, lifestyle changes, obesity rates or other environmental influences.”