Diverticular disease is a condition in which small pockets or out-pouchings occur in the bowel. These pockets (diverticula) can remain trouble-free or they can become inflamed or infected and cause symptoms.
When the out-pouchings of diverticular disease become inflamed, the condition is called diverticulitis.
Eating a low-fibre (‘Western’) diet results in stools with a consistency that requires high pressures to be generated in the bowel in order for a stool to pass. Diverticular disease is thought to result from these high pressures in the bowel forcing the lining of the bowel to pocket outwards through the surrounding muscle layer of the bowel.
People who eat a diet high in fibre are much less likely to develop diverticular disease. About one-third of adults older than 45 years have diverticular disease, although for most their diverticula cause them no problems.
Diverticular disease generally causes no symptoms. Sometimes mild cramping, constipation or bloating can occur. (These symptoms are common to many conditions, so their presence does not always mean you have diverticular disease, but you should see your doctor for advice if they occur.)
If the pouches retain faeces they can become inflamed and infected causing pain and local tenderness in the left lower abdomen, fever, nausea and loss of appetite.
If complications such as this develop, symptoms can include bleeding from the bowel (when a blood vessel in the pouch breaks), or increasing and persistent pain and fever (when an abscess develops and/or ruptures or the pouch itself ruptures into the abdominal cavity). Although rare, these complications of diverticulitis are serious and usually require emergency treatment in hospital.
To diagnose diverticular disease it is necessary to examine the inside of your bowel. This may be done via: colonoscopy (insertion of a lighted tube via your rectum, through which the doctor can see your bowel wall); or ‘virtual’ colonoscopy (a CT scan that produces a 3-D image of your bowel on a computer screen without the need to pass a tube into your rectum).
People with bowel pouches which have not become inflamed generally only require a change to a high-fibre diet to reduce the risk of symptoms and complications developing. The diet must include good quantities of roughage. Fibrous fruits such as apples and pears are best, along with other fresh fruits, vegetables and wholegrain cereals. Baked beans and legumes, such as kidney beans and lima beans, are very high in fibre, but may cause problems with wind in some people. The Digestive Health Foundation recommends 30 g of dietary fibre a day for people with diverticular disease. A simple way to increase the fibre in your diet is to add a bulking agent such as unprocessed wheat bran or psyllium seed husks (available from pharmacies under various brand names).
When the bowel pouches have become inflamed (diverticulitis), treatment is aimed at resting the bowel, relieving pain with analgesic medicine and fighting infection with antibiotics. A low-fibre or fluid-only diet is recommended initially to rest the bowel. After a month of eating a low-fibre diet, a high-fibre diet (as described above) is usually resumed.
Serious complications of diverticulitis such as marked bleeding or pouch rupture require hospital treatment, which may include emergency surgery to remove the affected area of bowel, stop any bleeding and drain areas of infection. A temporary colostomy opening may be made by the surgeon. Once the infection has settled the bowel will be rejoined in another operation and the colostomy closed.
Sometimes non-emergency surgery is planned to remove an area of bowel containing diverticula which have caused recurring diverticulitis in the past or which have joined onto another structure such as the bladder.
Last Reviewed: 25 November 2009