What Does a Diverticulitis Attack Feel Like?

A diverticulitis attack usually feels like sharp abdominal pain on the left side of your belly. Other symptoms can include fever, chills, constipation, diarrhea, nausea, and vomiting.

This article describes what you may experience if you are having a diverticulitis attack and how to know when the symptoms require a call to a healthcare professional.

A person with a hand on their stomach while lying down

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Diverticular disease is an umbrella term that includes both diverticulosis and diverticulitis, as well as diverticular bleeding.

Symptoms of a Diverticulitis Attack

Abdominal pain is the most common symptom of a diverticulitis attack, also called a flare-up. It might be felt in the lower-left quadrant (quarter) of the abdomen, the lower-right quadrant, or at the pubic bone. The pain might come and go or be constant.

The symptoms of a diverticulitis attack can be similar to many other common digestive problems. Some of the symptoms can include:

  • Bloating
  • Constipation
  • Diarrhea
  • Fever
  • Loss of appetite
  • Nausea
  • Mucus in the stool  
  • Urinary frequency
  • Vomiting

How Long Does a Diverticulitis Attack Usually Last?

In around 95% of people with uncomplicated diverticulitis, an attack usually lasts a week or less before subsiding on its own. The other 5% require treatment with antibiotics, a liquid diet, and—rarely—surgery before they get symptom relief.

How Do You Know If You Are Having a Diverticulitis Attack?

If you've already been diagnosed with diverticulosis or have previously experienced a flare-up of diverticulitis, you might assume you are having an attack—and you might be right.

If your symptoms are unfamiliar or different than they were during another attack, you may need to be evaluated to rule out other possible causes.

Other conditions that can be mistaken for diverticulitis include appendicitis, inflammatory bowel disease, and colorectal cancer.

When to See a Healthcare Provider

Even if you already know you have diverticular disease, it's important to call your healthcare provider for advice on what steps you should take.

You should also call a healthcare provider if constipation, diarrhea, vomiting, or fever have gone on for more than a few days.

Get emergency care if you are experiencing:

  • Sharp abdominal pain
  • Bleeding from the rectum
  • Fainting
  • Feeling confused, bleeding
  • An inability to keep any food or water down

Risks of Untreated Diverticulitis

It’s important to have diverticulitis evaluated and treated. Without treatment, there could be complications such as:

  • Anemia: A low number of healthy red blood cells from blood loss
  • Perforation: A tear that causes the contents of the large bowel to leak into the abdomen
  • Peritonitis: Infection of the abdominal cavity lining
  • Abscesses: Pockets of infection
  • Bowel obstruction

Preventing a Diverticulitis Attack

It’s not known exactly what causes diverticular disease. However, quitting smoking, eating as healthy a diet as possible (one that contains high fiber and includes less red meat), exercising, and maintaining an appropriate weight are all recommended to try to avoid a flare-up or complications from diverticular disease.

A healthcare provider can offer instructions on which of these lifestyle changes may be helpful.


The main symptom of a diverticulitis attack is pain on the left side of the abdomen. Symptoms such as diarrhea, constipation, fever, and nausea are also possible. Sometimes it is necessary to rule out other causes before arriving at a diagnosis of diverticulitis.

In the majority of cases, a diverticulitis attack will resolve within a week with conservative treatment.

Frequently Asked Questions

  • What is the difference between a diverticulitis attack and a flare-up?

    These two terms are interchangeable. Both a diverticulitis attack and a diverticulitis flare-up refer to the onset of symptoms of diverticulitis.

  • Will diverticulitis go away on its own?

    Diverticulitis might resolve with treatment at home that includes a liquid diet. For some more serious symptoms, antibiotics or treatment in the hospital might be needed.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & causes of diverticular disease.

  2. InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); Diverticular disease and diverticulitis: Treating acute diverticulitis. 2018 May 17.

  3. Ohio State University School of Nursing. Diverticular disease case study. Differential diagnosis. Autumn 2017.

  4. National Institute of Diabetes and Digestive and Kidney Diseases. Diagnosis of diverticular disease.

  5. Onur MR, Akpinar E, Karaosmanoglu AD, Isayev C, Karcaaltincaba M. Diverticulitis: a comprehensive review with usual and unusual complicationsInsights Imaging. 2017;8(1):19-27. doi:10.1007/s13244-016-0532-3

  6. National Institute of Diabetes and Digestive and Kidney Diseases. Treatment for diverticular disease.

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.