Study reveals alarming rise in severe diverticulitis among Americans under 50

A comprehensive analysis of more than 5.2 million hospitalizations reveals an alarming increase in cases of severe diverticulitis among Americans younger than 50.

The analysis, led by researchers from UCLA and Vanderbilt University and published in the journal Colon and rectal diseaseslooked at hospital admissions for adult patients with diverticulitis in the US from 2005 to 2020. The researchers found that the proportion of younger patients among those admitted with complicated diverticulitis, a subtype of diverticulitis that includes abscesses, perforations or other serious complications, increased from 18.2% to .

First study 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 that population having seen similar increases in colon cancer diagnoses.

“We’re seeing a significant change in people being hospitalized for severe diverticulitis,” said Kim, a fourth-year medical student at the David Geffen School of Medicine at UCLA. “This condition has traditionally been thought of as a disease of the elderly, but our data show that younger Americans are increasingly affected and often with more complex presentations.”

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

But UCLA’s analysis of the National Inpatient Sample, the largest publicly available inpatient health care database for all payers 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 under 50 years of age. Of these early-onset cases, the number of people admitted to hospital for complicated diverticulitis increased from 18.5% to 28.2%.

Kim said this represents a significant disease burden in a demographic area historically at lower risk.

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

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

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

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

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

Shineui Kim of UCLA Health

The researchers said more research into the possible causes of the increasing burden of early diverticulitis remains poorly understood. With similar increases seen in this population for colon cancer,

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