What Is Diverticulitis?

Diverticulosis is a condition in which small pouches, called diverticula, form in the wall of the colon (large intestine). This is very common, especially as people get older. Most people with diverticulosis never have any problems. However, when one or more of these pouches become inflamed or infected, the condition is called diverticulitis.

What Causes Diverticulitis?

The exact cause is not fully understood, but several factors contribute:

• Genetics: About half of the risk for diverticulitis comes from inherited (genetic) factors. If a close family member has had diverticulitis, your risk may be higher.
• Diet: A diet low in fiber and high in red meat and refined carbohydrates (white bread, pastries, sugary foods) is associated with increased risk. A diet rich in fruits, vegetables, whole grains, and legumes may help reduce risk.
• Obesity: Being overweight, especially carrying extra weight around the midsection, increases risk.
• Sedentary lifestyle
• Smoking
• Certain medications: Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs such as ibuprofen and naproxen) or opioid pain medications can increase risk

Important: Eating nuts, corn, popcorn, or fruits with small seeds (like strawberries and blueberries) does NOT increase the risk of diverticulitis. This is a common myth.

Symptoms of Diverticulitis

• Pain in the lower left side of the abdomen (this is the most typical symptom)
• Fever
• Nausea, with or without vomiting
• Changes in bowel habits (constipation or diarrhea)
• Loss of appetite
• Bloating

 

Uncomplicated vs. Complicated Diverticulitis

About 85% of diverticulitis cases are “uncomplicated,” meaning the inflammation is limited to the area around the diverticula without serious complications. The remaining 15% are “complicated,” which may involve:

• Abscess: A pocket of pus near the inflamed area
• Perforation: A hole in the colon wall
• Fistula: An abnormal connection between the colon and another organ (such as the bladder or vagina)
• Stricture: Narrowing of the colon from scarring
• Peritonitis: Infection spreading into the abdominal cavity (a surgical emergency)

 

How Diverticulitis Is Diagnosed

Evaluation begins with assessment of symptoms, physical exam, and blood tests. However, symptoms alone are only accurate about 40% to 65% of the time, so imaging is usually needed, usually a CT scan.

Treatment

Most people with uncomplicated diverticulitis can be treated at home without being admitted to the hospital.

• Pain management: Acetaminophen (Tylenol) is the preferred pain reliever. Avoid NSAIDs (ibuprofen, naproxen) as they may worsen the condition.
• Diet: You may be advised to start with clear liquids and gradually return to a normal diet as symptoms improve.
• Antibiotics (not always needed): Recent research has shown that many healthy patients with mild, uncomplicated diverticulitis recover well without antibiotics. Your doctor will decide whether antibiotics are necessary based on your overall health and the severity of your symptoms.

Complicated diverticulitis usually requires hospitalization and may include:

• Intravenous (IV) antibiotics
• Abscess drainage: If an abscess is present, it may be drained using a needle guided by CT imaging
• Surgery: Required for serious complications such as free perforation with peritonitis, large abscesses that cannot be drained, fistulas, or bowel obstruction. Surgery typically involves removing the affected section of colon.

Important: About 2% of patients who have acute diverticulitis have an underlying colon cancer.  After an episode of diverticulitis, patients should have a colonoscopy if they have:

• Complicated diverticulitis
• Unintended weight loss
• Blood in the stool
• Iron deficiency anemia
• Persistent abdominal pain
• Change in bowel habits
• Concerning features on CT scan

This colonoscopy is generally planned 6-8 weeks after acute diverticulitis to allow for healing.

 

Preventing Future Episodes

After recovering from diverticulitis, eating a high fiber diet, staying physically active, maintaining a healthy weight, and avoiding smoking and NSAID pain medications can all decrease your risk of further episodes.