New research finds a sharp increase in complicated diverticulitis cases in adults under 50.
A growing number of younger Americans are being hospitalized for severe forms of diverticulitis, a condition once thought to affect mostly older adults. A new analysis of more than five million hospital records between 2005 and 2020 found that patients under 50 now make up a much larger share of serious diverticulitis cases than in years past. The research, led by teams from UCLA and Vanderbilt University, uncovered a steady and sharp rise in younger adults experiencing complicated cases that involve abscesses, perforations, or other major problems in the colon.
Researchers found that the percentage of younger patients admitted for these serious cases jumped from 18.5 percent in 2005 to 28.2 percent in 2020—a 52 percent increase. Lead researcher Shineui Kim from UCLA Health said the data shows a meaningful shift in who is most affected by the disease. Historically, diverticulitis has been associated with aging, as the walls of the colon weaken over time. Now, younger adults are facing the same condition, often with more complex medical challenges. The finding adds to a growing concern, since early-onset colorectal cancer has also been rising among people in their 30s and 40s.
Diverticulitis occurs when small pouches form in weak spots along the colon wall. These pouches can become inflamed or infected, leading to symptoms such as abdominal pain, bloating, bleeding, and bowel changes. While most cases can be managed without surgery, complicated forms can become dangerous and may require hospitalization or procedures to remove part of the colon. The study used data from the National Inpatient Sample, a large national hospital database, to capture long-term changes in patient trends. Of the 5.2 million adults hospitalized for diverticulitis during the 15-year period, more than 837,000 were under 50.
Even though more young people are being hospitalized, treatment has evolved. The study showed that the number of younger patients needing surgery dropped from 34.7 percent to 20.3 percent during the study window. Researchers believe this reflects improved approaches in managing the disease with antibiotics, dietary changes, and close monitoring. At the same time, younger adults appeared more likely than older patients to need procedures such as drainage for abscesses or emergency colectomies, suggesting that while their overall outcomes may be better, the disease often appears more aggressive when it strikes early.
The findings also revealed differences in hospital experiences between age groups. Younger patients typically stayed in the hospital for shorter periods—less than a full day shorter on average—and their hospital bills were about $1,900 less per visit than those of older patients. Mortality rates were also lower among younger adults. Yet despite these encouraging figures, the higher rate of intervention raises questions about what drives the disease to develop more severely at younger ages.
Researchers said the causes behind this trend remain unclear. Rising obesity rates, diet patterns low in fiber, increased stress, and changes in the gut microbiome have all been suggested as possible factors. Environmental influences and lifestyle differences between generations may also be contributing. Kim said that while doctors are getting better at handling diverticulitis without surgery, the increase among younger people points to a wider health concern that demands further study.
The full study, published in Diseases of the Colon & Rectum, emphasizes the need for deeper research into prevention and early detection. Understanding what’s fueling the rise in early-onset cases could help improve treatment, shape public health messaging, and guide lifestyle recommendations for at-risk adults. Until then, doctors are encouraging awareness of symptoms such as persistent abdominal pain, unexplained changes in bowel habits, and recurring digestive discomfort. Recognizing the condition early can make a major difference in treatment outcomes and long-term health.
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Study reveals a troubling surge in severe diverticulitis among Americans younger than 50
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