Diverticular Disease

Diverticula are small pouch-like protrusions that develop in the wall of the large intestine (colon). Although they can occur throughout the colon, they are most commonly found in the lower part, known as the sigmoid colon. In adults—particularly those over 60 years old—diverticula are very common, found in about half of the population.

Types of Diverticular Disease

Diverticulosis:
This term refers to the presence of diverticula in the colon without causing symptoms or complications. It is generally a silent condition but may progress to complications such as diverticulitis, perforation (rupture), stricture (narrowing), fistula, or bleeding.

Diverticulitis:
This refers to inflammation or infection of one or more diverticula, usually when one of the pouches becomes blocked and ruptures. This can lead to secondary complications, collectively referred to as complicated diverticulitis.

Complications of Diverticulitis

  • Perforation and abscess formation: When the bowel wall ruptures, pus-filled abscesses may form as the body attempts to wall off the infection. If infection spreads throughout the abdominal cavity, peritonitis may develop, a life-threatening condition.

  • Rectal bleeding (bright red or maroon blood from the anus)

  • Stricture formation: Narrowing of the colon that obstructs stool passage.

  • Fistula formation: Abnormal connections (tunnels) between the colon and another organ or the skin. The most common type is a colovesical fistula (between the colon and bladder). Fistulas may also occur between the colon and the skin, uterus, vagina, or another part of the intestine.

Causes of Diverticula Formation

The widely accepted theory suggests that diverticula form in areas of high pressure within the colon. Increased pressure causes the intestinal wall to bulge outward through weak spots—especially where blood vessels penetrate the muscle layer.
Factors that contribute include:

  • Slow intestinal transit (constipation)

  • Low-fiber diets

  • High consumption of red meat

These conditions increase pressure and make stool harder, promoting diverticula formation. The precise mechanism that leads to inflammation of these pouches (diverticulitis) is still not fully understood.

Symptoms

Most individuals with diverticulosis have no symptoms or complications.
When diverticulitis develops, symptoms may include:

  • Pain in the lower abdomen (usually on the left side)

  • Fever

  • Rectal bleeding

  • Abdominal tenderness

The severity of these symptoms varies depending on the intensity of the inflammatory attack.

Diagnosis

Since diverticulosis is usually asymptomatic, it is often discovered incidentally during a colonoscopy or imaging studies such as abdominal CT scans performed for other reasons.
In patients with symptoms suggestive of diverticulitis, abdominal CT is the preferred diagnostic method, helping to confirm the diagnosis and assess complications.

Treatment

Patients with asymptomatic diverticulosis generally require no specific treatment but are advised to adopt a high-fiber diet rich in fruits and vegetables and limit red meat consumption to help prevent complications.

Most cases of acute diverticulitis can be treated successfully with oral or intravenous antibiotics.
If an abscess is present, image-guided drainage using a catheter may be necessary.

Surgical treatment is indicated in the following cases:

  • Peritonitis due to bowel perforation and leakage of stool or pus into the abdominal cavity (a surgical emergency)

  • Abscess that cannot be effectively drained with imaging-guided techniques

  • Severe disease not controlled with high-dose antibiotics

  • Immunocompromised patients (e.g., organ transplant recipients or chemotherapy patients)

  • Colon stricture or fistula formation

  • Recurrent attacks of diverticulitis despite optimal medical management

During surgery, the diseased segment of the colon is removed.
In emergency situations where there is widespread contamination of the abdominal cavity, a temporary colostomy or ileostomy (bringing the bowel to the surface of the abdomen to collect stool in a bag) may be required to allow the bowel to heal safely.