Signs Your Diverticulitis Could Be in a Flare-Up

Updated July 23, 2026

If you’ve ever felt the steady, sharp abdominal pain of a diverticulitis attack, another flare-up is probably not something you want to experience again. But chances are, you’ll likely have another. Studies show that more than half of the people who experience diverticulitis once are likely to have another flare-up.

Diverticulitis is a condition caused by inflammation or infection of diverticula, small pockets on the inside of the intestine. If one of the pockets becomes infected, it can lead to diverticulitis. 

“Diverticula may form as people get older, particularly if they’re overweight, don’t exercise and eat a low-fiber diet,” says Steven Koerner, D.O., FACOI, gastroenterologist at Hackensack Meridian Medical Group. “In most people, these extra bulges along the colon wall don’t cause health problems, and most people don’t realize that they have them. But when diverticula become inflamed or infected, the resulting diverticulitis can be quite painful.”

Symptoms of a Diverticulitis Flare-Up

If you think that you may have diverticulitis, or you’ve been diagnosed and think you’re having a flare-up, call or see your doctor.

Common symptoms of diverticulitis include:

• Constant abdominal pain that lasts for days, typically on the lower left side of the abdomen (although some people experience it on the lower right side)
• Nausea and/or vomiting
• Fever and/or chills
• Constipation or diarrhea
• Abdominal tenderness or cramping
• Rectal bleeding

You’re more likely to experience a diverticulitis flare-up if you are:

• Over age 40
• Overweight or obese
• A smoker
• Physically inactive
• Someone whose diet is high in animal products and low in fiber 
• Someone who takes non-steroidal anti-inflammatory drugs (NSAIDs), steroids or opioids

Treatment for a Diverticulitis Flare-Up

If you’re having a diverticulitis flare-up, your doctor can prescribe antibiotics to fight the infection. Be sure to take the medication for the full course as prescribed, rather than stopping when you start to feel better. Your doctor may also suggest that you:

• Consume a liquid diet or a low-fiber diet until your flare-up improves
• Rest as needed
• Sometimes, doctors recommend surgery for people with more serious flare-ups or recurrent diverticulitis. Surgical removal of the affected portion of the colon (and the infected or inflamed diverticula) should resolve the problem.

How to Lower Your Risk of Diverticulitis Flare-Ups

“It may not be possible to guarantee that you’ll never have another diverticulitis flare-up, but you can lower your risk of a recurrence if you follow certain healthy lifestyle habits,” says Dr. Koerner.

To avoid a diverticulitis flare-up, Dr. Koerner suggests adopting habits like these:

• Eat a high-fiber diet, with plenty of whole grains, fruits and vegetables
• Drink plenty of water
• Exercise regularly
• Quit smoking

In the past, doctors told people with diverticulitis to avoid popcorn, nuts, large and small seeds (pumpkin seeds, sesame seeds and everything in between) and foods that contain seeds (including tomatoes and strawberries). But, Dr. Koerner says this is an outdated recommendation, and you can eat these foods unless they cause you discomfort.

Next Steps & Resources

• Meet our expert: Steven Koerner, D.O., FACOI
• Make an appointment online with a doctor near you, or call 800-822-8905. 
• Learn more about our digestive services.