Diverticulitis (diverticular disease)

Diverticula are pouches that form in the intestinal mucosa. They are often harmless. However, diverticula can also lead to recurring or long-term symptoms. This is then diagnosed as chronic diverticular disease or diverticulitis. Learn more about the different types.

At a glance

  • Diverticula are pouches that form in the affected area of the intestinal mucosa.
  • The interior wall of the intestine bulges outward through the intestinal muscles.
  • Diverticula are often harmless and do not require treatment.
  • Diverticular disease can lead to symptoms or complications.
  • The pouches found in cases of diverticulitis are inflamed.
  • The inflammation can be treated with antibiotics.

Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.

Diverticulitis (intestinal disease): man holding his stomach with both hands.

What are diverticula?

Diverticula are pouches that form in the intestinal mucosa. The interior wall of the affected area of the intestine bulges outward through the intestinal muscles. Typically, this causes small balloon-shaped bulges in the intestine. Stool can accumulate in them.

Diverticula in the intestine are often harmless but can lead to symptoms and pain.

Simply put, there are three types:

  • Diverticulosis: the interior wall of the intestine bulges outward in several places. The bulges do not cause symptoms.
  • Diverticular disease: the bulges lead to symptoms or complications.
  • Diverticulitis: the bulges are inflamed.

Diverticula can lead to recurring or long-term symptoms. In this case, it is called chronic diverticular disease. Generally speaking, diverticulitis can be treated successfully. However, there can be serious consequences if the inflammation spreads.

How are diverticula noticed?

Diverticula seldom cause problems.

Most diverticula do not cause symptoms. Diverticular disease often causes pain in the left abdomen while very rarely in the right. Typical indications are bloating, constipation, or diarrhea. Symptoms are often temporary, but can persist. In many cases, the symptoms become more intense after eating and then improve after a bowel movement. Diverticula can sometimes also bleed. 

Diverticulitis (intestinal disease): woman sitting on the toilet holding a roll of toilet paper in her hand.

Diverticulitis often causes sudden, dull pain in the abdomen. This can be accompanied by a slight fever. Other symptoms include constipation, diarrhea, bloating, nausea, and sometimes cramps. Vomiting is less common. When the doctor presses on the stomach during an examination, the stomach muscles tighten reflexively; this is known as muscular defense. When released suddenly, the pain increases.

What are the causes of diverticulitis?

Risk factors for diverticulitis are age, weak connective tissue, bowel movement disorders, a genetic risk and being overweight.

Diverticula form in areas where there are weak intestinal muscles. Typically, they appear in the S-form part of the lower intestine known as the sigmoid colon. In this 40 to 45-cm long region above the rectum, pressure caused by the stool pressing against the interior wall of the intestine is the greatest.

Some people are more susceptible to diverticula for genetic reasons. Diverticulosis occurs more often in older or obese people. Further risk factors include weak connective tissue and impaired bowel movements. The impact of lifestyle on the disease is still unclear.

Evidence indicates that a diet low in fiber can increase the risk of diverticular disease, because this type of diet can cause constipation and a hard bowel movement. Other possible factors are a diet with too much red meat, smoking, and a lack of exercise.

The reason for the presence of diverticula in some people and not in others is still unknown, as is what increases the risk of contracting the disease. One possible factor is poor circulation and formation of hard feces particles in the diverticula.

How common is diverticulosis?

Around 50% of people over 70 have diverticula.

Many people do not notice that they have diverticulosis. Diverticula occur more often with age. Approximately ten percent of people under the age of 50 and 50 percent of those over 70 have diverticula. They occur as frequently in men as they do in women.

Approximately one percent of all people with diverticulosis develop diverticulitis within ten years. Inflammation can occur at any age.

How can diverticulitis be prevented?

People with diverticula can protect themselves from symptoms or inflammation. A fiber-rich diet is important to ensure that the stool does not become too hard. Whole-grain products, vegetables, legumes, and fruit are rich in fiber. In addition, exercise stimulates digestion. It is unclear if these measures actually protect from symptoms.

Some dietary recommendations advise against certain foods, for example, nuts, seeds, corn, and popcorn.

It has long been suspected that small residuals of these foods can be caught by the diverticula and lead to inflammation there. However, examinations have disproved this theory. This means that it is not necessary to forgo nuts, for instance.

How is diverticulosis diagnosed?

During a consultation, the doctor asks questions about preconditions and medications. During a physical examination, the doctor palpates and listens to the rectum and stomach. Depending on the symptoms, blood is drawn and urine is collected; the patient’s temperature is also taken. Normally, an ultrasound is performed.

If the diagnosis is still uncertain, computed tomography and, in some cases, a colonoscopy is needed.

During the examination, other diseases such as irritable bowel syndrome or appendicitis are ruled out as well. Their symptoms can resemble those of diverticular disease.

A colonoscopy may not be performed if the patient is currently suffering from diverticulitis. The patient should wait four to six weeks after the case of diverticulitis has healed to have a colonoscopy performed. The procedure helps to rule out the possibility of polyps, intestinal cancer, or other diseases.

How is diverticulitis treated?

Diverticula that do not cause symptoms do not require treatment. The degree of severity determines how the diverticulitis is treated.

The objectives of the treatment are to:

  • prevent complications that could result from an infection and alleviate symptoms,
  • prevent recurrence, and
  • alleviate chronic symptoms.

Diverticulitis can be treated with antibiotics. They are effective because inflammation of the diverticula is caused by bacteria.

If acute diverticulitis does not improve or if long-term symptoms appear, an operation may be necessary during which the affected section of the colon is removed. Because of the risks, the procedure should be carefully weighed. In the event of severe complications, such as peritonitis, an operation is necessary.

If symptoms are chronic, a diet rich in fiber may be helpful. The effect of foods with probiotics in alleviating symptoms is not entirely clear.

Much evidence suggests that antibiotics and operation are not necessary as often as once thought.

For more information about treatments for acute diverticulitis, visit gesundheitsinformation.de.

In cooperation with the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen) (IQWiG).

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