Diverticulitis & Diverticulosis

Diverticulitis and Diverticulosis Facts

Image of diverticuli in the colon.
Picture of diverticulitis.
  • Diverticulosis is a condition that describes small pouches in the wall of the digestive tract that occur when the inner layer of the digestive tract bulges through weak spots in the outer layer. When these diverticula become inflamed, that is called diverticulitis.
  • One of the main causes of diverticulosis is a diet low in fiber.
  • Many people with diverticulosis have no symptoms. When symptoms do occur they can include:
  • Diverticulitis is more serious and symptoms can include:
  • Diagnosis of diverticulosis/diverticulitis is made by a physical exam, which may include a digital rectal examination, blood tests, X-rays or CT scans of organs in the abdomen, a colonoscopy, or a flexible sigmoidoscopy.
  • Treatment for diverticulosis includes a diet high in fiber, fiber supplementation if needed, plenty of fluids, and exercise.
  • Diverticulitis also is treated with antibiotics and sometimes surgery.

What Is Diverticulitis?

Picture of diverticulitis, diverticulosis, diverticular disease
Picture of diverticulitis, diverticulosis, diverticular disease

Diverticula are small pouches in the wall of the digestive tract. They occur when the inner layer of the digestive tract bulges through weak spots in the outer layer. (This is similar to what happens when an inner tube bulges through a tire.)

  • Although these pouches can occur any place from the mouth to the anus, most occur in the large intestine (colon), especially the left (lower) portion of the colon just before the rectum.
  • These marble-sized pouches usually occur where the blood vessels run through the intestinal wall.
  • Individuals who have these pouches have diverticulosis.
  • Because this condition typically does not cause symptoms, most people are unaware they have diverticulosis.

What Are the Signs and Symptoms of Diverticulitis?

Most people with diverticulosis have no symptoms. When symptoms do occur, they are usually mild and include:

  1. Pain in the belly (abdomen)
  2. Bloating
  3. Constipation (less often, diarrhea)
  4. Cramping

These symptoms are nonspecific. This means that similar symptoms are seen in many different digestive disorders. They do not necessarily mean that a person has diverticulosis. If an individual has these symptoms, he or she should see a health-care professional.

Diverticulitis is a more serious condition and causes symptoms in most people with the condition that include:

  1. Pain in the abdomen, usually in the lower left side
  2. Bleeding, bright red or maroon blood may appear in the stool, in the toilet (a symptom of rectal bleeding), or on the toilet paper. Bleeding is often mild and usually stops by itself; however, it can become severe.
  3. Fever
  4. Nausea
  5. Vomiting
  6. Chills
  7. Constipation (less often, diarrhea)

If diverticulitis is not treated promptly it can develop some very serious complications. A complication is suggested by any of these symptoms:

  1. Worsening abdominal pain
  2. Persistent fever
  3. Vomiting (no food or liquid can be tolerated)
  4. Constipation for an extended period of time
  5. Burning or pain during urination
  6. Bleeding from the rectum

Diverticulitis vs. Diverticulosis


Diverticulitis is inflammation of diverticula. Diverticulitis occurs when one or more of these pouches becomes inflamed or infected. Some people with diverticulosis become aware of the condition only when acute diverticulitis occurs.


  • Diverticulosis is a very common condition in the United States.
  • Diverticulosis is mainly a condition of older people.
  • A small percentage of Americans over the age of 40 have diverticulosis. As we age, the condition becomes more prevalent. Over half of people older than 60 years of age develop the condition, and about two-thirds of individuals older than 80 years of age are believed to have diverticulosis.
  • Only a few people with diverticulosis will develop diverticulitis.
  • Diverticulosis is more common in developed or industrialized countries.
  • In places such as the United States, England, and Australia, where the typical diet is low in fiber and high in highly processed carbohydrates, diverticulosis is common. The current theory is that a low-fiber diet may cause increased incidence of diverticular disease.
  • Diverticulosis first appeared in the United States in the early 1900s. This was about the same time when processed foods were first introduced into the U.S. diet.
  • Diverticulosis is much less common in countries of Asia and Africa, where the typical diet is high in fiber.
  • Most people recover from diverticulitis without complications if they receive appropriate treatment.
  • Diverticulitis can lead to some very serious conditions if it is not detected and treated promptly.
  • To a great extent, diverticulosis and diverticulitis can be prevented by changes in diet, lifestyle and habits.

What Causes Diverticulitis and Diverticulosis?

Diverticulosis is thought to be caused by increased pressure on the intestinal wall from inside the intestine.

  • As the body ages, the outer layer of the intestinal wall thickens. This causes the open space inside the intestine to narrow. Stool (feces) moves more slowly through the colon, increasing the pressure.
  • Hard stools, such as those produced by a diet low in fiber or slower stool "transit time" through the colon can further increase the pressure.
  • Frequent, repeated straining during bowel movements also increases the pressure and contributes to the formation of diverticula.

Diverticulosis in developed countries is blamed largely on a diet low in fiber.

  • Fiber is found in fruits and vegetables, whole grains, and legumes (beans, peas, and lentils).
  • There are two types of fiber; soluble (dissolves in water) and insoluble.
    • Soluble fiber forms a soft gel-like substance in the digestive tract.
    • Insoluble fiber passes through the digestive tract nearly unchanged.
  • Both are necessary to in the diet keep stool soft and moving easily through the digestive tract.
  • This is how fiber prevents constipation.

When Should You Call a Doctor for Diverticulitis?

A person should see a health care professional if he or she has any of the following symptoms, which may indicate a serious condition:

  • persistent abdominal pain, often in the lower-left area of the abdomen;
  • persistent unexplained fevers;
  • persistent diarrhea;
  • persistent vomiting; or
  • persistent or recurring urinary tract infection.

Any time a person has bleeding from the rectum, he or she should see a health-care professional as soon as possible.

  • Seek medical care even if the bleeding stops on its own.
  • Bleeding may be a sign of diverticulitis or other serious diseases.
  • If there is a lot of blood or a steady flow of blood, go to a hospital emergency department immediately.

The following symptoms suggest a complication and warrant an immediate visit to an emergency department:

  • worsening abdominal pain;
  • persistent fever with abdominal pain;
  • vomiting so severe that food or liquids cannot be tolerated;
  • swelling or distention of the abdomen;
  • persistent constipation for an extended period of time; or
  • severe pain or other symptoms that you had before when you had diverticulitis.

A person should not attempt to drive themselves to receive medical help, they should have someone else drive them, or call 911 for emergency medical transport.

What Tests Diagnose Diverticulitis and Diverticulosis?

The health care professional will ask the patient questions about his or her symptoms, lifestyle and habits, and medical and surgical history.

  • The physical exam will probably include a "digital rectal examination" in which a health care professional inserts a gloved finger into the rectum to try to find a cause for bleeding or pain.
  • Blood tests may be performed to access signs of blood loss or infection, evaluate the function of the kidneys and liver, or to rule out other medical conditions that could be causing similar symptoms.
  • X-rays of organs in the abdomen may be ordered to assist in identifying the cause of the patient's symptoms.
  • CT scans are similar to X-rays except they are able to visualize the organs better and often provide the health care professional with more useful information. One drawback with CT scans is that they are more expensive, and take longer to perform.
  • A colonoscopy is a procedure performed using a flexible tube with a tiny camera at the end, called an endoscope. The endoscope is inserted into the rectum and further up into the colon. The endoscope provides a direct view of the inner lining of the colon and rectum. The procedure is relatively painless and usually takes 30 to 45 minutes. Patients may be given a sedative medication to relax during the procedure.
  • A flexible sigmoidoscopy is a procedure performed with a flexible sigmoidoscope that has a tiny camera at the end of the sigmoidoscope. The patient lies on his or her left side while the instrument is inserted through the anus and advanced through the rectum and colon. This procedure is relatively painless and takes about five minutes.

Sometimes diverticulosis is discovered during a screening colonoscopy. The American Cancer Society and the United States Multi-Society Task Force on Colorectal Cancer recommend colonoscopies every 10 years for people older than 50 years to detect early signs of colon cancer. If an individual's family medical history includes a close relative diagnosed with colon cancer, they may need to begin screening at an earlier age. Consult a gastroenterologist for guidelines.

What Foods Are Good for a Diverticulitis Diet?

A high-fiber diet is the mainstay of diverticulosis and diverticulitis prevention.

  • Start a high-fiber diet because it will decrease the risk of complications and the accompanying symptoms; however, will not make the diverticula a person has go away. Foods high in fiber include:
    • Whole-grain cereals and breads
    • Fruits (apples, berries, peaches, pears)
    • Vegetables (squash, broccoli, cabbage, and spinach)
    • Beans, peas, and lentils.
  • Drinking plenty of fluids will also help the stool stay soft and pass quickly to prevent constipation and decrease the risk for diverticulosis.
  • Get plenty of physical activity to keep bowels functioning properly.

In the past patients with diverticulosis/diverticulitis were told that foods to avoid included seeds, corn, and nuts because it was thought fragments of these foods would get stuck in the diverticula and cause inflammation. However, current research has not found this to be the case, and the fiber content of such foods may actually benefit individuals with diverticulosis/diverticulitis. Discuss your diet or potential diet changes with your doctor.

What Is the Medical Treatment for Diverticulitis and Diverticulosis?

Treatment for Diverticulosis Symptoms

Diverticulosis with symptoms is usually treated as follows. This therapy is designed to soften stools and help them pass faster, which removes the conditions that cause diverticula in the first place.

  • High-fiber diet for diverticulitis (some health care professionals recommend a fiber supplement to prevent constipation)
  • Clear fluids
  • Mild pain medications

Treatment for Diverticulitis

Treatment for diverticulitis depends on the severity of the condition.

  • Simple cases can be treated by a health care professional at his or her office, and by a patient following a high fiber diet.
  • Treatment for uncomplicated cases usually consists of antibiotics and bowel rest. This usually involves 2-3 days of bowel rest, taking in only clear fluids (no food at all), so the colon may heal without having to work.
  • Complicated cases typically involve severe pain, fever, or bleeding. If an individual has any of these symptoms, he or she will probably be admitted to the hospital. Treatment consists of IV or oral antibiotics, bowel rest, and possibly surgery.

What Natural or Home Remedies Help Relieve Diverticulitis Pain?

As mentioned previously, eat a diet high in fiber, drink plenty of fluids, and exercise regularly to keep the bowels functioning properly and prevent constipation.

How Successful Is Surgery for Frequent or Severe Diverticulitis Attacks?

If diverticulitis attacks are frequent or severe, the doctor may suggest surgery to remove a part of the patient's colon.

  • As with any surgery, there are risks the patient should discuss with his or her doctor.
  • Sometimes the operation requires at least two separate surgeries on different occasions.

What Are the Recovery Times and Complications of Diverticulitis?

Most people recover fully after treatment. If not treated promptly, however, diverticulitis can lead to the following more serious conditions and complications:

  • Perforation: A hole in the intestine caused when the diverticular pouch bursts because of increased pressure and infection within the intestine.
  • Peritonitis: A more serious infection of the abdominal cavity that often occurs after perforation, when the contents of the intestine leak out into the abdominal cavity (peritoneum) outside of the intestine.
  • Abscess: A pocket of infection that is very difficult to cure with antibiotics.
  • Fistula: An abnormal connection between the colon and another organ that occurs when the colon damaged by infection comes in contact with another tissue, such as the bladder, the small intestine, or the inside of the abdominal wall, and sticks to it. Fecal material from the colon can then get into the other tissue. This often causes a severe infection. If fecal material gets into the bladder, for example, the resulting urinary tract infection can become recurrent and very difficult to cure.
  • Blockage or obstruction of the intestine
  • Bleeding in the intestine

Of the people who are admitted to a hospital for diverticulitis, some develop complications that require surgery.

Individuals younger than 40 years of age who have depressed immune systems from medications or other illnesses have a greater chance of having complications and having to undergo surgery.

Approximately 50% of people who have diverticulitis will have a relapse within 7 years after the condition is treated and in remission. The second episode may be worse than the first. See a health care professional at the first sign of recurring symptoms.

Can Diverticulitis Be Prevented?

Eating a high-fiber diet will not only decrease a person's chance of getting diverticulosis and diverticulitis; it will benefit health in other ways such as by lowering the risk of colon cancer and possibly heart disease.

Which Specialties of Doctors Treat Diverticulitis and Diverticulosis?

You may initially be diagnosed with diverticulosis or diverticulitis by your primary care provider (PCP), such as a family practitioner, an internist, or child's pediatrician. You may also see an emergency medicine specialist in a hospital's emergency department. You will likely be referred to a gastroenterologist, a specialist in the digestive tract, for further treatment.

Colonoscopy for Diverticulitis and Diverticulosis Diagnosis

A colonoscopy is a medical procedure that doctors use to diagnose diseases of part of the gastrointestinal (GI) tract, for example, celiac disease, colon polyps, diverticulitis, colitis, Crohn's disease, and cancers of the GI tract. Part of the preparation or "prep" for colonoscopy may include a combination of:

  • a liquid diet
  • laxatives, or
  • enemas.
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Pemberton, JH, MD, et al. "Acute colonic diverticulitis: Medical management." UpToDate. Jan 2020.

Pemberton, J.H., MD. "Patient information: Diverticular disease (Beyond the Basics)." UpToDate. Jan 2020.

Shahedi, K. MD. "Diverticulitis." Medscape. Updated: Aug 05, 2019.