Treatment for diverticulitis focuses on clearing the infection, reducing inflammation, resting the colon and preventing or minimizing complications. In most cases, hospitalization is not required, unless signs and symptoms are severe (e.g., vomiting, fever above 100 degrees Fahrenheit [37.8 degrees Celsius], very high white blood cell count) or the patient is elderly, has an increased risk of complications or has a weakened immune system.

Antibiotics, given in pill form, are generally used to treat bacterial infection for patients treated outside the hospital. Patients who must be hospitalized generally receive intravenous antibiotics. In most cases, the symptoms go away after three to four days of antibiotic therapy. These medications are typically continued for seven to 10 days after symptoms clear to ensure that the infection is gone.

Pain medications, both over-the-counter and prescription, may be used. However many of these have a tendency to cause constipation and aggravate diverticulitis, so some physicians may not recommend them. Antispasmodics are occasionally used for some patients.

Bed rest is generally recommended for patients with diverticulitis. Patients should avoid activities that increase pressure in the abdomen (e.g., lifting, straining, bending). Patients are frequently placed on a clear liquid or low-fiber diet. This allows the inflammation to clear and the bowels to rest. Once the symptoms go away, patients can begin gradually adding fiber to their diet.

Few diverticulitis patients require surgery. Surgery may be recommended for a number of reasons, including:

• Symptoms do not respond to medical treatment.
  
  
• Complications are present.
  
  
• Cancer cannot be ruled out.
  
  
• The patient has a weakened immune system.
  
  
• The patient has had two or more attacks. This is because subsequent attacks tend to be more serious and increase the chance of complications. Some physicians may recommend surgery following the first attack in patients under the age of 40 years for similar reasons.

The surgical treatment for diverticulitis is colon resection (anastomosis). The diseased region of the colon is removed and the healthy sections are joined together to allow normal bowel function. This procedure may be performed as an open (traditional) surgery involving a single long incision, or a laparoscopic surgery (using a device called a laparoscope for imaging) involving three or four tiny incisions.

If there is extensive infection or obstruction, it may be unsafe to rejoin the sections of the colon that were not removed. In these cases, a colostomy is performed. During this procedure, the colon is connected to a hole (stoma) that is created in the abdomen. Stool then empties into a pouch attached to the stoma. This allows normal eating and bowel movements. The stoma is usually closed and the sections of the intestine are reconnected in a second surgery 10 to 12 weeks after the first. However, the colostomy may be permanent in some patients.

Abscesses may clear up with antibiotics alone. However, they may require drainage using a catheter and needle inserted into the abscess through the skin. Large abscesses may require surgical removal. Fistulae may also be surgically removed. The diseased portion of the colon is typically removed at the same time. Peritonitis usually requires immediate, emergency surgery to clean the abdominal cavity and remove the diseased portion of the colon.

Surgery for diverticulitis is very safe. Complications are rare, but may include risks generally associated with anesthesia (e.g., allergic reaction, cardiac and breathing difficulties) and surgery (e.g., bleeding and infection). Risks specifically related to colon surgery include:

• Injury to an organ
• Injury to the blood vessels
• Hernias through the surgical incisions
• Breakdown of the anastomosis