Diverticular Disease of the Colon

Diverticulae are areas of out-pouching of the colonic lining (mucosa) due to weakness in the muscular wall of the colon. It is a condition that does not cause any symptoms and is common in affluent societies. Up to 75% of people over the age of 75 will have diverticulae and less than 10% will develop problems related to this.

pic1The wall of the colon is made up of circular fibers and longitudinal fibers. At the areas where these fibers cross, potential weaknesses can occur. The lining (or mucosa) bulges out through this weakness and a diverticulum is formed. The small blood vessel supplying the mucosa also runs through this weakness.

Colonoscopy view of uncomplicated diverticulae

Colonoscopy view of uncomplicated diverticulae

 Risk factors for development of diverticulae:

Genetic predisposition is an important component for the development of diverticulosis. Aspirin and other non-steroidal anti-inflammatories (like ibuprofen and diclofenac ) have been shown to increase the risk of diverticulitis. Other risk factors for diverticulitis include obesity and lack of exercise.

What do people with diverticulae complain of?

The majority of patients with colonic diverticulosis will never develop symptoms. Those who present with symptoms can be classified into 3 broad categories:

  • Part of the Irritable Bowel Syndrome (IBS)
  • Diverticulitis
  • Bleeding


IBS and diverticulae:

Irritable bowel syndrome is very common and the symptoms often investigated with a colonoscopy to exclude other diseases. In many of these patients the colonoscopy will show uncomplicated diverticulae. The diverticulae are most-often an innocent by-stander and not the cause of the symptoms. No treatment is needed.


Infection of a diverticulum is called diverticulitis. Patients typically present with abdominal pain, fever and an upset tummy (nausea, vomiting, constipation or diarrhoea). Some patients may have other symptoms like burning urine. A general practitioner can treat mild, uncomplicated attacks of diverticulitis with oral antibiotics. More complicated attacks need hospital admission and intravenous antibiotics. In severe cases the infection may need to be drained using a small drain through the skin. Some patients become desperately ill and require emergency surgery. If this happen, a colostomy or ileostomy is usually needed.


The small vessel that supplies the mucosa of the diverticulum can sometimes start to bleed. Patients often present with a sudden onset of a large amount of bright red bleeding from the rectum and have no pain. Dizziness or fainting can sometimes happen. The bleeding almost always stops spontaneously. Very seldom it is necessary to do an emergency colonoscopy to stop the bleeding.

What should you do if diverticulae were found at colonoscopy?

Diverticulae generally are not dangerous and cannot lead to cancer. In the past many people advocated avoiding certain types of foods. There is no evidence to support this. To prevent more diverticulae from forming, one should increase the amount of dietary fiber, avoid non-steroidal anti-inflammatory drugs and increase your level of fitness and exercise. Surgery is seldom indicated and used only if there are severe complications from diverticulitis or recurrent bleeding.