What Age Do People Get Diverticulitis?

Taken together, around 18 percent of members who responded were diagnosed before the age of 40, a proportion many people find surprising given how often diverticulitis is described as a condition of later life. The largest single cluster, just over a quarter of respondents, was diagnosed between 41 and 55. But diagnosis in the 56 to 70 range was almost exactly as common, at around 36 percent.

As one member put it when the poll results came in: “I’m intrigued as we’ve had several posts from younger people recently which goes against the accepted norm.” Younger diagnoses are a real and recurring pattern in our community, not an occasional exception.

Is Diverticulitis Only A Condition Of Older People?

No, but age is a major risk factor.

Diverticular disease becomes more common as we get older. According to the NHS, diverticula are rare under 40 but affect around half of people over 50 and up to 70 percent of people over 80. However, most people with diverticulosis never develop diverticulitis.

You can read more about diverticular disease on the NHS website.

In our group, diagnoses ranged widely:

• • 21 years old, diagnosed after a barium enema
  • 22, diagnosed by colonoscopy
  • 27, diagnosed via CT scan
  • 34 and 36, confirmed by CT followed by colonoscopy
  • 40s and 50s, often during routine colonoscopy or after a first painful flare
  • 60s and 70s, sometimes with no prior symptoms at all

“Rebecca from Kent” shared that she was diagnosed at 28 and is now 56. She usually has one or two flares a year.

“Laura from Manchester” was 63. She had never had any symptoms before her first attack. It was labelled uncomplicated diverticulitis after a CT scan.

“Nadia from Brighton” was just 22. “Denise from Rotherham” has lived with it for around ten years, having been diagnosed in her 40s, and still finds certain meals trigger diarrhoea. “Carol from Preston” was diagnosed at a similar age to Rebecca but did not need surgery on her colon and bladder until much later, at 68, after four years of managing flares.

The range itself can feel unsettling. There is no single ‘typical’ age.

What Is the Difference Between Diverticulosis and Diverticulitis?

This is one of the most common sources of confusion.

• • Diverticulosis means small pouches have formed in the bowel wall.

• • Diverticulitis means those pouches have become inflamed or infected.
    
    

Several members described being told they had diverticulosis years before any flare occurred.

“Dana from Bristol” was diagnosed with diverticulosis at 41 during a colonoscopy. Her first diverticulitis flare happened five years later.

Others experienced a flare without ever knowing they had diverticula in the first place.

This difference matters. Many people live with diverticulosis and never develop diverticulitis. Read more about the difference here.

Is a Colonoscopy Standard After a First Flare?

This was one of the most debated questions in our community.

Short answer: often yes, but timing and necessity depend on individual circumstances.

Many members reported:

• • CT scan in hospital during acute pain

• • Follow-up colonoscopy weeks or months later

“Rachel from Belfast” had a CT scan at 36 during a flare. A colonoscopy followed a month later. She has another scheduled and admits she dreads it.

“Donna from Leeds” was diagnosed via CT during her first flare. A colonoscopy in September confirmed diverticular disease.

Current UK practice commonly involves a colonoscopy after a first episode of diverticulitis, especially if it was confirmed by CT. The purpose is to:

• • Confirm the diagnosis

• • Exclude other conditions such as bowel cancer

• • Assess the extent of diverticular disease

However, colonoscopy is usually delayed until inflammation has settled, often six to eight weeks later, to reduce the risk of complications.

Not everyone continues to have regular colonoscopies. One member in her late 50s shared that her clinicians are cautious about repeat procedures because of extensive diverticulosis and the theoretical risk of perforation.

This highlights something important: recommendations are personalised.

Why Are More Younger People Being Diagnosed?

There are a few possible reasons:

• • • Increased use of CT scanning means diverticulitis is identified more accurately

• • • Lifestyle factors such as diet, obesity and physical inactivity may contribute

• • • Greater awareness means people seek help earlier

That said, diverticulitis under 40 is still less common than in older age groups, and current research is starting to quantify what that group looks like in more detail.

A 2024 US study focusing specifically on diverticulitis in patients aged 18 to 40 (Diverticulitis in the Under-40 Population, PMC11016325) reviewed the records of 109 younger patients treated for acute diverticulitis. Of those, 40 required surgery and 69 were managed conservatively without an operation. The strongest predictor of which patients needed surgery was the severity of disease at presentation, known clinically as the Hinchey classification, rather than age itself. The authors also noted that as diverticulitis has become more common in recent decades, the frequency of elective surgery for the condition has risen alongside it.

This matters for younger members of our community for two reasons. First, it confirms that a diagnosis under 40 is a real and increasingly recognised pattern, not a statistical fluke. Second, it suggests that how severe a first flare is matters more than a person’s age when it comes to predicting whether surgery will eventually be needed.

For someone diagnosed at 27, as one of our members was, the experience can feel isolating. Most online information appears to focus on older adults. Yet younger cases are real, and our own poll data, alongside research like this, confirms they are not rare.

Does Family History Matter?

Possibly.

“Dawn from Sheffield” was diagnosed at 54 but had known she had diverticulosis since 50. Her mother suffered with it for years.

Research suggests genetics may play a role, although diet and lifestyle are also significant contributors.

Family history does not guarantee you will develop diverticulitis, but it may increase awareness and prompt earlier investigation.

What Do Flares Feel Like, And Does Severity Depend On Age?

While this discussion focused on age, many comments referenced symptoms, and one theme came through strongly: severity does not track neatly with how old a person is when diagnosed.

• • Left-sided abdominal pain
  • Flank pain
  • Sudden severe pain requiring hospital admission
  • Pain resolving with antibiotics and a liquid diet

For some, like “Karin from Glasgow,” the first episode was severe, involving a perforated sigmoid colon and emergency surgery with temporary colostomy formation.

Several other members described similarly serious first presentations at very different ages. “Margaret from Wrexham” was 49 when she needed an emergency laparotomy for a perforated bowel, an abscess and peritonitis, requiring a stoma and later a reversal. “Pauline from Luton” had lived with IBS most of her life but was 55 when she was diagnosed with diverticulitis alongside an abscess and a hole in her bowel, needing a Hartmann’s procedure and a colostomy bag, which she says saved her life. At the other end of the age range, “Vera from Hull” was 74 when her bowel perforated and she now lives with a permanent colostomy.

Equally, some of the most severe complications in our group happened to relatively young members. “Michelle from Dundee” was 28 when diagnosed and is now, at 49, awaiting bowel resection surgery because of three significant narrowings.

For others, flares were labelled uncomplicated and managed with antibiotics and dietary modification, regardless of age. “Gordon from Watford”, diagnosed in his early 60s, spent a week in hospital, changed his diet and increased his exercise, and has had no further flares since.

The emotional experience was consistent across ages: shock, fear, confusion and questions about what comes next.

FAQs

Why Does This Feel So Confusing?

Because there is no single path.

One person has mild flares every year. Another has a single severe episode at 63. Someone else lives for decades with diverticulosis before anything happens.

When you are newly diagnosed, particularly in your 50s or 60s, it can feel like the ground has shifted beneath you. You may be wondering:

• • Is this the start of something chronic?

• • Will I need surgery?

• • Should I change my diet completely?

• • Why did this happen now?

These are reasonable questions. And the answers are rarely one-size-fits-all.

Key Takeaways

• • Diverticulitis is most common over 50, but it can occur much younger, including in your twenties
  • Our community poll of several hundred members found around 18 percent were diagnosed before age 40, with diagnoses spread fairly evenly across every decade from the 40s through to the 70s
  • Many people have diverticulosis without ever developing diverticulitis
  • CT scans are commonly used to diagnose acute flares
  • Colonoscopy is often recommended after a first episode, once inflammation has settled
  • Research on patients aged 18 to 40 shows that disease severity, not age, predicts whether surgery will be needed
  • Experiences vary widely in frequency and severity, at every age

More Reading

What Foods Trigger Diverticulitis?

Can Stress Trigger Diverticulitis Symptoms?

What Can Be Mistaken For Diverticulitis?

What Is The Difference Between Diverticulitis And Diverticulosis (Diverticular Disease)?

What Triggers Diverticulitis Flare Ups?

If you have been recently diagnosed and feel uncertain about what comes next, you are not alone. Our forum at Diverticulitis Club exists to provide calm, balanced peer support alongside evidence-based information.

You can join the discussion or read others’ experiences here:
https://diverticulitis.club/forum/

Disclaimer: This article does not constitute medical advice. Medical advice should always be sought from a qualified medical practitioner.