Diverticular Disease

Diverticulosis is a condition in which small pockets called diverticula develop in the intestines. Although these pouches can form anywhere, including the throat, stomach and small intestine, most occur in your large intestine. They often form on the left side, just above the rectum, where solid wastes leave the body.

Diverticulitis is a condition in which the pouches become inflamed or infected, causing severe pain, fever and nausea. Fortunately, only about one out of every five people with diverticulosis ever develop diverticulitis.


Diverticulitis can feel like appendicitis (a painful, potentially life-threatening infection of the appendix). The main difference is that the pain is felt in the lower left side of your abdomen instead of the lower right. The pain is usually severe and sudden, but sometimes it starts out mild and gets worse over several days. Other possible symptoms are abdominal tenderness, fever, nausea, constipation and diarrhea. Less common symptoms of diverticulitis may include:

  • Vomiting
  • Bloating
  • Bleeding from the rectum
  • Frequent urination
  • Difficulty or pain while emptying the bladder of urine


Causes and Risk Factors

Diverticula develop when naturally weak places in the colon give way under pressure, often from straining to push out solid wastes from the body over several years. Sometimes a bit of stool (solid waste) may become lodged in one of the pouches, leading to infection. A small tear can also develop in a pouch, causing an infection inside the abdomen.

As we age, the outer muscular wall of the colon thickens, causing the inside passage to narrow. This narrowing increases the pressure in the colon and raises the chances pouches will form. Thickening of the outer wall also makes moving waste from the colon more difficult, and the waste stays in the colon longer, becoming harder and dryer. Too little fiber makes small, hard stools that are hard for the body to pass, which causes even more colon pressure.


Most people learn they have diverticulosis during routine screening exams for colorectal cancer or tests for other intestinal problems. These tests include:

  • Colonoscopy, a test in which a flexible, lighted tube is used to view the large intestine
  • Sigmoidoscopy, a test similar to colonoscopy except that it examines the lower part of the colon
  • Colon X-ray

Diverticulitis, on the other hand, is usually diagnosed during a painful attack. Diverticulitis can range from minor inflammation to a massive infection. Because it can be serious, a doctor should be consulted immediately. A diagnosis is based on:

  • Tenderness in the abdomen
  • A blood test indicating a high white blood cell count
  • A test such as a computerized tomography (CT) scan, which will show the pouches that are inflamed or infected.


Treatment for diverticulitis depends on the severity of symptoms and the number of attacks. Mild symptoms may be treated with a liquid or low-fiber diet and antibiotics until the infection is gone. Patients may need to avoid whole grains, fruits and vegetables until the colon has healed. The doctor may suggest resting quietly for a few days. Pain relievers may be prescribed if pain is present.

Other treatments are needed for a fever over 100º F, vomiting or other severe symptoms. These include:

  • Intravenous (IV) antibiotics may be needed, particularly for patients who are older or those who have a high white blood cell count, a risk of blockage that keeps solid wastes from moving through the intestines, peritonitis (an infection of the lining of the abdominal cavity), another disease or a weakened immune system.
  • Surgery may be needed to remove the diseased part of the colon and reconnect the healthy parts. This can either be done traditionally or using minimally invasive techniques.

A colostomy may be either permanent or temporary, depending on the amount of inflammation. The surgeon makes an opening in the abdominal wall, and the colon is connected to the opening so that wastes can pass through it into a bag.