What is Diverticulitis?

Diverticula are pouches that form in the digestive system, most commonly in the wall of the large intestine. Feces can get trapped in the pouches, promoting the growth of bacteria. This leads to the inflammation or infection of the diverticula, which is known as diverticulitis.

What causes Diverticulitis?

Doctors aren’t sure what causes the formation of diverticula. The presence of diverticula is called diverticulosis. Diverticulosis may never develop into diverticulitis. For many years, scientists believed that a low-fiber diet caused diverticulosis. Without fiber to add bulk to the stool, the large intestine has to work harder to push it through the digestive system, and pressure from this may cause weak spots which eventually turn into pouches. However, a recent study indicated that a low-fiber diet is not associated with diverticulosis. Clearly, more research is needed.

Who is at risk?

Studies have found links between diverticulitis and obesity, sedentary lifestyle, smoking, and certain medications, like NSAIDs and steroids. Diverticulitis is rarer in countries where people eat high-fiber diets, so too little fiber in the diet may increase risk as well. People over the age of 40 are more prone to diverticulitis, potentially because the strength and elasticity of the large intestine decreases over time, leading to an increased likelihood of diverticulosis.

Signs and Symptoms

The most common symptom of diverticulitis is a sudden, severe pain in the lower left side of the abdomen. The pain may worsen when the patient moves. Some people experience mild abdominal pain that worsens over the course of a few days, but this is less common than sudden, severe pain. The abdomen may feel swollen, tender, or sore, and gas and bloating are common. Changes in bowel habits, such as diarrhea or constipation, can also indicate diverticulitis, as well as fever and chills. Patients may experience nausea and vomiting. In severe cases, diverticular bleeding can be present, indicated by blood in the stool.

Symptoms of Diverticulitis:

  • Sudden, severe pain in the lower left side of the abdomen (or mild pain that worsens over time)
  • Diarrhea or constipation
  • Swollen, tender, or sore abdomen
  • Gas and bloating
  • Fever and/or chills
  • Nausea and vomiting
  • Blood in the stool


If diverticulitis is suspected, your doctor will first conduct a rectal exam and blood test. The blood test can indicate inflammation or anemia; too few red blood cells may indicate that there is bleeding in the large intestine. A fecal occult blood test checks for blood in the stool, and an abdominal X-ray can rule out other issues.

After these routine tests, the doctor may want a better look at your large intestine. Because there is a risk of the pouch bursting, some tests that are frequently performed for other abdominal issues are not frequently used if diverticulitis. For example, sigmoidoscopies, colonoscopies, and barium enemas are not often done because the large intestine could perforate, causing the infection to spill into the abdominal cavity lining.

CT scans are less invasive and are commonly used to identify and diagnosis diverticulitis, and to rule out other conditions.


Treatments for diverticulitis often involve a change in diet. The doctor may recommend a liquid diet for a few days to give the infection time to heal. Antibiotics may also be prescribed. Patients should increase the amount of fiber in their diets to prevent future attacks. Tylenol and other NSAIDs may ease mild pain. If the pain is severe or the patient cannot drink liquids, he or she made need to stay in the hospital and receive nutrition through an IV. In fewer than 6% of cases, patients will require surgery.

Most cases of diverticulitis improve in two or three days. Occasionally, complications may occur, such as an abscess, perforation, or bowel obstruction. In these instances, surgery may be required.

High-Fiber Foods:

  • Black, navy, and kidney beans
  • Whole-grain cereal
  • Apples, pears, raspberries, and prunes
  • Squash, sweet potato, and green peas
  • Cauliflower, broccoli, spinach, and corn
  • Sunflower seeds, almonds, peanuts
  • Quinoa, brown rice, whole-grain breads and pasta
  • Flaxseed