Diverticulitis: Causes, Symptoms, and Treatments

If your colon could talk, diverticulitis would be the moment it says,
“I’ve had enough of this low-fiber life.” This common digestive condition sounds
intimidating, but understanding what’s going on inside your gut can make it a lot
less scary. In this guide, we’ll break down what diverticulitis is, why it happens,
what symptoms to watch for, and how it’s typically treated and prevented all in
clear, down-to-earth language.

What Is Diverticulitis, Exactly?

To understand diverticulitis, you first have to meet its quiet cousin:
diverticulosis. Over time, small pouches called
diverticula can form in the lining of your colon, especially in the
lower left side. This is diverticulosis, and it’s extremely common after age 40. Most
people with diverticulosis never know they have it and never develop symptoms.

Diverticulitis happens when one or more of those pouches become
inflamed or infected. That’s when the drama starts: pain, fever, and a generally
unhappy abdomen. In some people, inflammation stays “uncomplicated,” meaning it’s
limited to the wall of the colon. In others, it can become complicated
diverticulitis with serious issues like abscesses, perforation (a small tear),
or infection spreading into the abdomen.

Doctors often use a few related terms:

• Diverticulosis: Diverticula are present, but no inflammation or symptoms.
• Diverticular disease: Diverticula plus chronic or recurring abdominal discomfort.
• Diverticulitis: Diverticula that are inflamed or infected, usually causing acute pain and illness.

How Common Is Diverticulitis and Who Gets It?

Diverticular disease is very common in Western countries. By age 60, well over half
of adults have diverticulosis, and a smaller percentage go on to develop diverticulitis.

Several factors raise your risk of diverticulitis:

• Age: Risk increases steadily after 40.
• Low-fiber, “Western” diet: Lots of red meat and processed foods, not enough fruits, vegetables, and whole grains.
• Obesity and physical inactivity.
• Smoking.
• Medications: Regular use of NSAIDs (like ibuprofen), steroids, and opioids has been linked to higher risk.
• Genetics: Family history can play a role too.

The good news? Many of these risk factors are modifiable which means lifestyle
changes can help reduce your chances of a flare or recurrence.

Causes and Triggers of Diverticulitis

From Diverticulosis to Diverticulitis

So what actually causes a quiet little pouch to become angry and inflamed?
Researchers believe diverticulitis happens when there’s increased pressure or
microscopic injury in the wall of a diverticulum. That can allow normal gut bacteria
to invade the tissue, sparking inflammation and sometimes infection.

Factors that may contribute include:

• Hard, dry stools pushing against the colon wall.
• Overall inflammation in the colon.
• Changes in the gut microbiome (your “good” and “bad” gut bacteria mix).

Risk Factors You Can Influence

Lifestyle doesn’t “cause” diverticulitis in a simple, one-to-one way, but it does
shape the environment inside your colon. Research suggests that:

• Higher fiber intake is linked with lower risk of diverticular disease and complications.
• High red-meat intake and typical Western dietary patterns raise the risk.
• Obesity, sedentary lifestyle, and smoking all increase your chances of diverticulitis.

Think of it this way: your colon prefers soft, bulky stools that move along smoothly,
not dry, compacted little bricks that slam into the colon wall.

Myths About Nuts, Seeds, and Popcorn

For years, people with diverticulosis were told to avoid nuts, seeds, corn, and
popcorn in case they “got stuck” in the pouches. Modern research has very politely
told that myth to sit down.

Large long-term studies show that eating nuts, seeds, and corn does not
increase the risk of diverticulitis or related complications. In fact, these foods
often come packaged with fiber and healthy fats, which may actually support colon
health.

Of course, if a particular food bothers you personally, it’s fine to avoid it
but you don’t have to fear every sunflower seed on the planet.

Symptoms: What Diverticulitis Feels Like

Typical Symptoms of Uncomplicated Diverticulitis

Classic diverticulitis symptoms tend to appear over hours to a couple of days and
often include:

• Pain in the lower left abdomen (though it can be on the right side or elsewhere).
• Tenderness when that area is pressed.
• Fever and chills.
• Nausea or vomiting.
• Changes in bowel habits constipation is common, sometimes diarrhea.
• Feeling bloated or gassy.
• Loss of appetite or just “feeling sick.”

Diverticulitis usually does not cause significant rectal bleeding. If
you notice a lot of blood in your stool, that needs prompt medical evaluation for
other causes.

Warning Signs of Complicated Diverticulitis

Sometimes inflammation goes deeper and leads to serious complications such as
abscesses, perforation, fistulas, strictures (narrowing), or widespread infection
in the abdomen (peritonitis).

Call your doctor right away or seek emergency care if you have:

• Sudden, severe or worsening abdominal pain.
• High fever or shaking chills.
• Rigid or extremely tender abdomen.
• Inability to pass gas or stool, or severe bloating.
• Signs of sepsis: feeling very ill, confusion, rapid heart rate, fast breathing.
• Urinary symptoms or passage of gas/stool in the urine (could signal a fistula).

These situations are medical emergencies and can require hospital care, drainage
procedures, or surgery.

How Diverticulitis Is Diagnosed

Your clinician will start with a detailed medical history and physical exam
(including gentle but not very fun poking of your abdomen). Common next steps may
include:

• Blood tests: Looking for signs of infection or inflammation, such as elevated white blood cell count or C-reactive protein.
• CT scan of the abdomen and pelvis with contrast: This is the gold-standard imaging test to confirm diverticulitis, show where the inflammation is, and detect complications like abscesses or perforation.
• Urine tests or pregnancy tests: To rule out other causes of abdominal pain.

A colonoscopy is usually not done during an acute flare
because the colon is inflamed and more fragile. Instead, many guidelines recommend
scheduling a colonoscopy a few weeks after recovery especially if you’ve never had
one or if there are concerns about other conditions like colorectal cancer.

Treatment Options for Diverticulitis

Treating Mild, Uncomplicated Diverticulitis at Home

Mild cases of uncomplicated diverticulitis can often be managed
at home under medical supervision. Typical treatment may include:

• Short-term diet changes: Many clinicians start with a clear liquid or low-fiber diet for a few days to let the colon rest, then gradually advance back to normal foods as pain improves.
• Pain control: Acetaminophen is often preferred over NSAIDs, since NSAIDs are associated with higher risk of complications in diverticular disease.
• Antibiotics (sometimes): Newer guidelines suggest that in otherwise healthy people with mild uncomplicated diverticulitis, antibiotics may be used selectively rather than automatically. In immunocompromised patients or those with more severe disease, antibiotics are usually recommended.
• Monitoring: You’ll be advised to call your provider or go to the ER if symptoms worsen or new red flags appear.

Never self-diagnose diverticulitis and treat it without medical advice abdominal
pain has many possible causes, some of them life-threatening.

When You Need Hospital Care

Moderate to severe diverticulitis, especially if you have fever, significant pain,
vomiting, or other health issues, may require hospital treatment. In that setting,
you might receive:

• Intravenous (IV) antibiotics targeting gut bacteria.
• IV fluids to prevent dehydration and support blood pressure.
• “Bowel rest” no food at first, then gradual reintroduction of liquids and soft foods.
• Pain management and close monitoring of vital signs and lab tests.
• Image-guided drainage of an abscess if one forms (a radiologist places a small tube through the skin to drain infected fluid).

If inflammation doesn’t improve, or if there’s a large perforation, severe abscess,
or widespread infection, surgery may be necessary.

When Is Surgery Recommended?

Surgery for diverticulitis is more targeted today than in the past. Instead of
automatically recommending surgery after a certain number of flares, clinicians look
at the whole picture: severity, complications, your overall health, and how much the
disease impacts your life.

Surgery may be considered if you have:

• Complicated diverticulitis with perforation, fistula, or obstruction.
• Recurrent episodes that significantly affect quality of life.
• Persistent symptoms despite medical management.
• Severe attacks in the setting of immunosuppression.

The most common operation removes the diseased segment of colon and reconnects the
healthy ends. In some emergency situations, a temporary colostomy (bag on the
abdomen) may be needed, but this is not always the case.

Preventing Future Diverticulitis Flares

Once you’ve had diverticulitis, it’s normal to want to avoid ever going through that
again. While no strategy can guarantee zero recurrences, lifestyle changes can lower
your risk.

Adopt a High-Fiber, Gut-Friendly Diet

After you’ve fully recovered (and your clinician gives the green light), most
experts recommend transitioning to a high-fiber diet to keep stools
soft and reduce pressure inside the colon.

General fiber goals often fall around:

• Women up to age 50: about 25 grams per day.
• Men up to age 50: about 31–34 grams per day.
• Slightly lower targets after 50, depending on guidelines.

Fiber-rich foods that support colon health include:

• Fruits (berries, pears, apples with skin).
• Vegetables (broccoli, carrots, leafy greens).
• Whole grains (oats, quinoa, barley, whole-wheat bread).
• Legumes (lentils, chickpeas, black beans).
• Nuts and seeds, which are now considered safe for most people with diverticulosis.

Increase fiber gradually and drink plenty of water to prevent gas and bloating as
your gut adjusts.

Move More, Smoke Less (Ideally Not at All)

Physical activity helps stimulate bowel movement and supports a healthy weight
both tied to lower risk of diverticulitis. Smoking, on the other hand, is associated
with higher risk of complications and recurrence. Guidelines also recommend keeping
BMI in a healthy range and avoiding unnecessary NSAID use when possible.

Living With Diverticulitis: Mind–Gut Matters

Diverticulitis doesn’t just affect your colon; it can also impact how you feel about
food, social events, travel, and your body in general. Anxiety about another flare
is common. Some people start to avoid entire categories of foods or feel nervous
leaving home.

A few strategies that can help:

• Work with a registered dietitian if possible to design a realistic, high-fiber eating plan.
• Ask your clinician for a clear “flare plan” so you know when to call, what to eat, and what medications to use.
• Keep a symptom and food diary to see patterns over time rather than guessing based on one bad day.
• Address stress and mental health: Gut and brain are closely connected, and managing stress can help you cope better.

The goal isn’t a “perfect” colon it’s a life where diverticulitis is managed,
understood, and not in charge of all your decisions.

Real-World Experiences and Practical Tips

Beyond the science and the guidelines, there’s the lived reality of having
diverticulitis. While every person’s experience is unique, many stories share a
familiar pattern: a sudden, unexplained pain, a trip to urgent care or the ER, a CT
scan with contrast, and that first moment hearing, “You have diverticulitis.”

People often describe that first flare as confusing. The pain can feel like a pulled
muscle, menstrual cramps, food poisoning, or appendicitis. Some try to “walk it
off,” only to realize that each step sends a sharp reminder from the lower left side
of the abdomen. By the time they seek care, they’re sometimes exhausted, dehydrated,
and worried about everything from cancer to surgery.

Once the diagnosis is made and treatment starts, the next big question becomes,
“What now?” The learning curve usually involves three themes:
food, fear, and flexibility.

On the food side, people quickly notice how many different opinions exist online.
One website tells them to avoid nuts forever; another says nuts are perfectly fine.
A friend swears that popcorn caused their attack. A relative insists you can never
eat tomatoes again. Over time, those who do best tend to step back from extreme
rules and instead focus on patterns: “How do I feel when I eat a very low-fiber
diet?” “Do I feel better when I include fruits, veggies, and whole grains most
days?” That observational, curious mindset is often more helpful than strict
lists of “good” and “bad” foods.

Fear is also a major player. After a painful flare, it’s completely normal to worry
about triggering another one. Some people avoid social events that involve food,
or cancel travel because they’re afraid of being far from a bathroom or hospital.
As they gain more experience living with diverticular disease and see that not
every gurgle or cramp means “emergency” confidence slowly returns. Having a clear
plan from a healthcare provider (“If X happens, call; if Y happens, go to the ER”)
can dramatically reduce that background anxiety.

Flexibility might be the most underrated skill. Many people with diverticulitis
learn that there are “recovery days” and “regular days.” During a recovery phase,
they might lean on softer, lower-fiber foods, more rest, and simple routines.
As symptoms fade, they can gradually shift back to their usual high-fiber pattern.
Being flexible means you don’t panic when your gut has an off day you adjust
and give it a little extra care instead.

Practical tricks also show up again and again in personal stories:

• Keeping go-to “gentle” meals on hand (like broth-based soups, mashed potatoes, yogurt, or oatmeal).
• Having a water bottle nearby and making hydration almost automatic.
• Taking short walks after meals to help stimulate digestion.
• Using reminders or apps to track fiber intake and bowel habits.
• Preparing a small “flare kit” with a heating pad, comfortable clothing, and any doctor-approved medications.

Many people also report that open conversations with family and friends make a big
difference. It’s easier to ask for understanding “Hey, I might need to leave
early if my stomach acts up” than to silently suffer and pretend everything is
fine. Over time, diverticulitis becomes one part of their health story, not the
entire narrative.

Perhaps the most encouraging theme from lived experience is this: with good medical
care, realistic lifestyle changes, and a bit of humor about the quirks of the human
gut, most people with diverticulitis go on to live full, active lives. Flares may
happen, adjustments will be needed, but the condition is manageable. Your colon may
be opinionated, but it doesn’t get the final say on your future.

Bottom Line

Diverticulitis happens when small pouches in the colon become inflamed or infected,
leading to symptoms like abdominal pain, fever, and changes in bowel habits. It’s
common, especially as we age, but it’s also highly manageable. Mild cases are often
treated with rest, short-term diet changes, and sometimes antibiotics, while more
serious or complicated cases may require hospitalization, drainage procedures, or
surgery.

Long-term, the focus shifts to prevention: a high-fiber diet, regular physical
activity, not smoking, maintaining a healthy weight, and using NSAIDs judiciously.
Modern evidence has also retired old myths about nuts and seeds, allowing more
flexibility and variety in the diet.

If you’ve been diagnosed with diverticulitis or diverticular disease, you’re not
alone and you’re not powerless. Partnering with your healthcare team, making
sustainable lifestyle changes, and understanding what’s happening in your colon can
help you move from fear to confidence. Always work with a medical professional for
a personalized treatment plan, and consider this article your friendly, slightly
nerdy companion along the way.