Diverticular disorders: Diverticulosis & acute diverticulitis

Diverticula are small, bulging sacs that form on the inner wall of the intestine. These sacs are usually located in the large intestine (colon). The presence of these diverticula is known as “diverticulosis”. Diverticulitis occurs when these sacs become inflamed or infected. This condition leads to fever and pain in the abdomen, usually the left side. The doctor treats this disease with the help of antibiotics. The diverticula remain in the intestine for life, which sometimes results in a return of symptoms. Finally, untreated diverticular disease may lead to serious complications.

  • Terminology diverticular diseases
  • Causes of diverticulosis and acute diverticulitis
  • Symptoms
  • Diagnosis and investigations in acute diverticulitis
  • Therapy
  • Prognosis of present or inflamed diverticula in the large intestine
  • Complications of diverticular disease

Terminology diverticular diseases

The term diverticulosis indicates the formation of bulging sacs or sacs (diverticula) on the intestinal wall. Diverticulitis means that these diverticula are inflamed. Doctors prefer to use the more general term diverticular disease as it is often difficult to diagnose inflamed diverticula.

Causes of diverticulosis and acute diverticulitis


Diverticula (sac-like bulges) are usually located in the large intestine and occur in 50% of patients over the age of fifty. They are most commonly found in the sigmoid (last part of the large intestine), but they are present everywhere along the large intestine. The precise mechanism of diverticulum formation is not known. Diverticular disease appears to be associated with the low-fiber diet consisting mainly of processed foods in developed countries.

Acute diverticulitis

Diverticulitis occurs when feces are trapped in these sacs. This causes a standstill that causes bacteria to multiply and produce inflammation. This leads to intestinal perforation (hole in intestine), abscess formation, fistulas to adjacent organs or even generalized peritonitis (inflammation of the peritoneum due to infection in the abdominal cavity).



Diverticular disease is asymptomatic in 95% of cases. A doctor usually discovers this by chance during a barium enema examination. Symptomatic patients experience recurring pain, bloating, cramps or discomfort in the lower abdomen and irregular bowel movements, sometimes in combination with pollakiuria (frequent urination). In severe cases, a narrowing occurs in the inside of the sigmoid, leading to more severe pain and constipation. Blood in the stool or on toilet paper is also possible. Finally, the patient occasionally presents with a volvulus (intestinal knot: twisting in the intestine with constipation, nausea and pain).

Acute diverticulitis

Acute diverticulitis most commonly affects diverticula in the sigmoid colon. The patient presents with sudden severe pain in the left side of the abdomen (an acute abdomen), in most cases accompanied by fever and chills, constipation, bloating, flatulence, nausea and vomiting, green stools, a loss of appetite and not eating. These symptoms and signs are similar to inflammation of the appendix of the appendix (appendicitis), but in the lower left part of the abdomen. In many patients, the symptoms worsen after a few days.

Diagnosis and investigations in acute diverticulitis

Physical examination

When examining the patient, the doctor notices fever in combination with an accelerated heart rate (tachycardia). The examination of the abdomen reveals a tender, stiff left side of the abdomen. Sometimes the doctor will feel a tender mass on the left side of the abdomen.

Diagnostic research

In the absence of clinical symptoms of acute diverticulitis, a colonoscopy (internal examination of the colon) or a barium enema in combination with flexible sigmoidoscopy (internal examination of the last part of the colon) is occasionally performed. Technically, it is sometimes difficult to get a sufficient view of the sigmoid area in diverticular disease. If the patient does have symptoms, the doctor will perform a blood test and a CT scan. These tests are often sufficient to confirm the diagnosis of acute diverticulitis and to rule out other malignant conditions. During an acute attack, the doctor does not perform sigmoidoscopy and colonoscopy. An ultrasound is also possible, although this is less accurate than a CT scan.

Differential diagnosis

When diagnosing acute diverticulitis, the doctor should be aware of other conditions with a similar clinical picture, such as:

  • acute inflammation of the pancreas with abdominal pain and digestive problems (pancreatitis)
  • acute inflammation of the stomach lining (gastritis)
  • acute pyelonephritis (inflammation of the kidney(s) and renal pelvis)
  • chronic mesenteric ischemia
  • constipation
  • cysts (abnormally shaped cavities in the body)
  • the presence of kidney stones (nephrolithiasis)
  • a biliary disorder
  • a bladder infection (cystitis) in women
  • Appendicitis
  • inflammation of the peritonium (peritonitis) and abdominal sepsis (blood poisoning)
  • a colonic obstruction
  • an intestinal perforation
  • inflammation of the fallopian tubes (salpingitis)
  • an enterovesical fistula
  • an inflammation of the gallbladder (cholecystitis: abdominal pain, fever and nausea)
  • a bile duct obstruction (blockage of the bile ducts)
  • an inflammatory bowel disease (inflammatory bowel disease)
  • a liver abscess
  • a stomach ulcer
  • an inflammation of the bile ducts with fever, abdominal pain and jaundice (cholangitis)
  • a rectovaginal fistula
  • a urinary tract infection in men
  • a urinary tract obstruction
  • biliary colic (abdominal pain due to gallstone blocking bile duct)
  • gynecological pain
  • irritable bowel syndrome (symptoms of diarrhea and constipation)
  • mesenteric ischemia
  • mesenteric thrombosis
  • pyogenic liver abscesses
  • viral gastroenteritis (stomach flu caused by a virus)



No specific treatment is required in asymptomatic patients. The treatment of uncomplicated symptomatic patients is with a balanced (soluble and insoluble) fiber-rich diet (20 g/day) with smooth muscle relaxants (spasmolytics) if necessary.

Acute diverticulitis

Acute attacks of diverticulitis are treated by the doctor on an outpatient basis using antibiotics. Patients who are sicker receive bowel rest, intravenous (through a vein) fluid administration, and intravenous antibiotics and other medications. After the patient is cured of diverticulitis, he will have another colonoscopy.

Prognosis of present or inflamed diverticula in the large intestine

Once these diverticula form, they remain for life. Diverticulitis sometimes returns, but a fiber-rich diet reduces the chances of a recurrence. A mild condition can usually be treated well. Some patients experience more than one attack of diverticulitis, sometimes requiring surgery.

Complications of diverticular disease

A perforation may occur, which usually, but not always, occurs in association with acute diverticulitis. This leads to the formation of an abscess or generalized peritonitis. Surgery is required in these circumstances. Fistula formation in the bladder is also one of the possible complications. This causes urinary problems, air in the urine or a discharge. Repeated episodes of acute diverticulitis may cause intestinal obstruction. A number of patients also develop massive bleeding. In most cases, the doctor determines the cause of these bleedings through a colonoscopy and sometimes an angiography (radiographic image of the blood vessels), and then he knows how to stop them. In rare cases, a surgical procedure is necessary in which the doctor removes part of the colon. Finally, mucosal inflammation sometimes develops in areas where diverticula are present, causing the appearance of segmental colitis during an endoscopy (internal examination of the inside of the body).

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Diverticular disorders: Diverticulosis & acute diverticulitis
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