Diverticulitis Symptoms, Diet, Foods To Avoid, Treatment, Surgery

What are Diverticula?

Diverticula (singular ~ diverticulum) are abnormal marble-sized pouches protruding out from the intestinal wall – most often from the sigmoid colon (Picture 1). It is more commonly seen with advancing age. Most of the time diverticula do not pose any significant health problem and may not even present with any symptoms. However, when these diverticula become infected then it can cause significant discomfort and other symptoms.

Diverticulosis as seen in colonoscopy

Picture 1. Diverticula in the colonic wall as seen during colonoscopy.

Most people who develop diverticula are over the age of 50 years. In fact as may as 2 in 3 people aged 85 years and older have diverticula. The majority of people do not experience any symptoms. However, it does affect about 1 in 5 people younger than 50 years. Overall only about 15% of people with diverticula develop diverticulitis. It can lead to serious complications like intestinal blockage and perforation, peritonitis and even sepsis in untreated cases.

Causes of Diverticulitis

Diverticula form when the bowel wall weaken and eventually small pouches form in the colon wall. This is a result of age-related changes which may cause weakening of the intestinal wall. Due to increased pressure within the colon, like when straining to pass stool in constipation, pouches can form slowly over time. The colon is laden with bacteria and these bacteria can enter and infect the pouches thereby leading to diverticulitis.

Signs and Symptoms

It is important to understand the differences between diverticulosis, where diverticula form in the colon, and diverticulitis, where the diverticula become infected. If diverticulitis symptoms or worsen despite treatment then it is imperative that immediate medical attention is sough. Some of the complications of diverticulitis can be serious and even life-threatening without prompt medical attention.

Symptoms of Diverticulosis

Diverticulosis refers to multiple intestinal (mostly colonic) diverticles, which commonly occur in old, but also in young constipated persons who constantly strain at defecation. Diverticula may cause no symptoms at all, or it may cause constipation, bloating, lower left side abdominal cramps or pain.

Symptoms of Diverticulitis

Diverticulitis refers to inflamed (mostly infected) diverticula. Symptoms may last from few hours to several days and include:

  • Lower left side abdominal pain and/or tenderness, or (in Asian populations) right side abdominal pain
  • Nausea
  • Diarrhea or constipation
  • Bloating and flatulence
  • Fever, chills
  • Vomiting (not common)


In both diverticulosis and diverticulitis the following complications may occur:

  • Inflammation of nearby organs such as the prostate, bladder and uterus may occur if the infection spreads from the sigmoid colon.
  • Obstruction of the colon due to scarring after several episodes of  inflammation. This may require immediate surgery.
  • Collections of pus (abscesses) in or around the colonic wall. Abscesses may be treated with antibiotics or surgery.
  • Perforation of the colon, which can lead to life threatening inflammation of the lining of the abdominal cavity (peritonitis). Symptoms of perforation are severe pain, fever and (if shock develops) weak and fast heart pulse, rapid breathing, restlessness. Colon perforation often requires urgent surgery.
  • A fistula (a tunnel through the tissues) may connect colon with adjacent organs (small intestine, bladder, uterus, vagina, skin of abdominal wall) and cause inflammation in the area and of these organs.
  • Intestinal bleeding (not common) may occur and sometimes it is not due to diverticula. Therefore the source of bleeding should be identified and treated.
  • Sepsis is more likely to develop if there is a severe infection that is untreated, especially if perforation is undiagnosed and treatment is delayed.

Diagnosis of Diverticulitis

Diverticulosis or diverticulitis may be suspected from symptoms, mostly from lower left abdominal pain. The presence of diverticles can be confirmed by ultrasound or CT of the abdomen. Blood test may show increased leukocytes. X-ray with barium enema or colonoscopy to evaluate the extent of diverticulosis may be performed after the inflammation has subsided.

Treatment of Diverticulosis and Diverticulitis

Diverticula are usually permanent and do not resolve with time, diet or medication. Surgery may be necessary in some instances. When diverticulitis does occur then the following treatment options may be considered.

  • Rest.
  • Clear liquid diet (water, clear juices, pop-sickles without fruit particles, gelatin, broths) or low-fiber diet (white bread, white rice, pasta, eggs, poultry, fish without bones, fruits without peels, membranes, or seeds).  Avoid vegetables with hard skins, like beans or peas.
  • Oral antibiotics in mild diverticulitis cases and intravenous antibiotics in severe infections.
  • Mild painkillers like paracetamol may be taken in pain. Strong painkillers (morphine) aggravate constipation so they should be avoided, if possible.

Diverticulosis and Surgery

If diverticles cause constant problems over the years, and diet does not help, a surgical removal of the affected part of the colon may help. Surgery can be performed through a classical open-abdomen surgery, or laparoscopic surgery with only few short incisions in the abdominal wall. In most cases, the remaining parts of the colon can be connected end-to-end but sometimes a temporary or permanent colostomy (a free end of the colon connected to abdominal wall) is needed.

Diet to Prevent Diverticulosis and Diverticulitis

After attack of diverticulitis is over, you can adjust your diet to avoid further developing of diverticles:

  • If you are constipated, eat enough fiber to soften the stool. Fruits, vegetables, cereals, nuts, whole-grain or half-white bread and fiber supplements, like psyllium husk, may all be appropriate. Introduce fibers slowly to prevent bloating (also do not exaggerate with an amount – you need enough, not a lot of fiber). Drink enough fluid together with the fiber.
  • If you are bloated, avoid fruits like apples, pears, plums, prunes and dried fruits in general, sugary foods and drinks. Citruses and berries may be fine.
  • Do not delay bowel movements when it is time to go, and avoid straining.
  • Be active. Exercise helps to prevent diverticula formation.

Foods To Avoid For Colon Diverticulitis

In the past it was recommended to avoid foods with hardly digestible peels like popcorn or beans or those with small seeds like strawberries, blueberries, cucumbers or tomatoes because they could lodge in diverticula and cause its inflammation. There no scientific evidence for these claims but these small food particles should be avoided in the event that a person with diverticula is uneasy about this occurring.


  1. Diverticulitis  (merck.com)
  2. Diet in diverticulitis  (mayoclinic.com)
  3. Foods to avoid in diverticulitis (mayoclinic.com)
About Jan Modric (209 Articles)
Health writer

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