Diverticulosis and Diverticulitis


What Is It?

Diverticulosis develops in weak spots along the walls of the colon, typically in the part of the colon called the sigmoid colon on the left side of the abdomen. In response to abnormal pressure in the colon, small, balloonlike pouches called diverticula may poke outward through the weak spots. Most people have no symptoms, but if a diverticulum bleeds or becomes infected, hospital care generally is required. Surgery may be recommended in specific circumstances.

The condition is more prevalent as people age. For example, it is estimated that half of people in the United States aged 60 to 80 have diverticulosis, but only one person in 10 develops it by age 40. It is equally common in women and men.

About 10 percent to 25 percent of people with this condition develop diverticulitis. This occurs when the diverticula become inflamed or infected. It is characterized by constant pain, usually in the lower abdomen, and often fever and other symptoms.

Diverticulitis can lead to serious complications such as abscess, perforation, intestinal blockage from internal scarring, or fistula, which is an abnormal connection between two organs. A rare but life-threatening complication called peritonitis can occur when diverticula rupture, leaking infection into the abdominal cavity.


Most people who have diverticulosis have no symptoms, but some have mild cramps, constipation or bloating. Diverticulitis has much more severe symptoms, including any of the following, but particularly the first two:

  • Steady abdominal pain
  • Tenderness to pressure in the lower abdomen
  • Fever
  • Nausea
  • Vomiting
  • Chills
  • Cramping
  • Change in bowel habits (constipation or diarrhea)
  • Rectal bleeding
  • Sharper pain with breathing or jarring movements such as walking.


The symptoms of diverticular disease can mimic other diseases, including irritable bowel syndrome, stomach ulcers, acute appendicitis, Crohn’s disease, bladder infection, kidney stones, colitis, or tumors of the ovary or colon.

Your doctor will ask about your medical history, bowel habits and diet and will conduct a physical examination, including a rectal examination with a gloved finger to detect tenderness, blockage or blood. Your doctor may press on your abdomen to check for tenderness. If inflammation is spreading, discomfort will remain even after the doctor removes the pressure. Sharper pain on movement, such as walking, suggests that an abscess may have ruptured.

Your doctor may order additional studies, including blood tests for signs of infection, a stool check for blood, and an X-ray, a Computed tomography (CT) scan or Ultrasound to look for diverticulitis or abscess inside the colon.

Expected Duration

Symptoms may subside within a few days after treatment, may persist, or may even grow worse in the case of severe illness or complications. Diverticula do not disappear unless the section of colon is removed surgically. Diverticulosis is a lifelong condition that can be managed, primarily with adjustments in diet.


People whose diets contain large amounts of fiber are less likely to develop diverticular disease. The American Dietetic Association recommends 20 to 35 grams of fiber a day, preferably from fruits, vegetables and grains. Your doctor also may recommend unprocessed bran or a fiber product. It is important to increase fiber intake gradually and to drink more water to increase the bulk of the bowel movements, which reduces pressure inside the bowel.

Physical activity also may lower the risk of diverticulosis. Many doctors previously recommended that people with diverticulosis avoid eating nuts, popcorn and foods with seeds. This restriction has not been proven to prevent diverticulitis.


The only treatment for mild diverticulosis is to increase fiber in the diet. Fiber will not heal existing diverticula, but it may prevent more from forming.

For diverticulitis, antibiotics will be prescribed, and the doctor may recommend a liquid diet and bed rest to help the colon recover. An acute attack with severe pain or infection may require a hospital stay so that antibiotics can be given intravenously (into a vein).

If fever persists, the doctor may suspect an abscess, which can occur when a diverticulum becomes perforated. An abscess is a collection of pus. A surgeon then will help your doctor plan the next step: drainage or surgery. The choice depends on the extent of the problem and your overall health. Drainage means that the surgeon cleans out the pus.

Emergency surgery is required to treat peritonitis, the most serious potential complication of diverticulitis. Peritonitis requires surgical repair as well as intravenous antibiotics. Up to 35 percent of patients with peritonitis die.

Surgery also may be required during the hospital stay to treat a particularly severe episode of diverticulitis or other complications. These include continuous bleeding, perforation of an abscess, attachment of two organs by a fistula, or colon obstruction caused by scarring from previous episodes of diverticulitis.

The most common procedure, known as a colon resection, involves removal of the part of the colon that contains diverticula and surgical reattachment of the ends. When performed during emergencies, a colon resection becomes a two-stage process. First, a section of colon is removed, but because of infection, it is not safe to rejoin the ends. Instead, the surgeon creates a temporary hole, or stoma, in the abdomen and connects the colon to it, a procedure called a colostomy. A bag is attached to collect the stool. At a later time, a second operation reattaches the ends of the colon, and thus the colostomy is removed. Sometimes, if the situation is not an emergency, the surgery can be done all at once.

After successful treatment for diverticulitis, your doctor normally will recommend a high-fiber diet and may order a colonoscopy, an internal examination of the colon, at a later date. Surgery usually is not recommended after only one attack without complications. However, it often is recommended after a second episode. Repeated episodes of diverticulitis can lead to internal scarring and narrowing of the colon, which also may require surgical removal of a piece of the colon.

When To Call A Professional

Call your doctor if abdominal pain in one spot persists for longer than a few hours, especially if it becomes worse or is accompanied by fever.


With proper treatment and adoption of a high-fiber diet, the prognosis for people with diverticulosis and uncomplicated diverticulitis is excellent. Most people with diverticulosis never have symptoms. Of those who are hospitalized for diverticulitis, improvement should occur within two to four days after treatment begins. Up to 85 percent of patients recover with bed rest, liquid diet and antibiotics, and most never have a second episode of diverticulitis. The prognosis varies if complications develop and is particularly serious in the case of peritonitis. If colon resection is performed, about 90 percent of patients have no recurrence of symptoms after the surgery.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.