Diverticular disease Dr Rob Hicks Diverticular disease is a condition affecting the large bowel or colon and is thought to be caused by eating too little fibre.

In this article

What causes it? Who's affected?

How's it diagnosed? What are the symptoms?

What is diverticulitis?

Over a lifetime, it's estimated the human gut digests more than 65 tonnes of food and drink. Much of this food will be low in fibre, putting the gut under strain.

One common outcome of this is diverticular disease, a condition affecting the large bowel, or colon, believed to be the result of too little fibre in the diet.

A diet low in fibre creates the ideal conditions for constipation to develop. When this happens, the pressure in the large part of the gut increases, which forces small parts of the gut lining outwards through the muscles surrounding the gut. This causes the lining to form small balloon-like pouches called diverticula.

About one in two adults over 50 is affected, and most adults are affected by the time they reach 90. Men and women are affected equally.

Diverticular disease is very uncommon in countries such as Africa, where diets are high in fibre. In Western countries, where many people still don't eat enough fibre, it becomes more common as people get older.

Unless the diverticula become inflamed, many people won't have any symptoms. They may only become aware they have diverticular disease when it's found by chance during tests for another problem.

Under these circumstances, to prevent future problems developing, it's advisable to increase the amount of fibre in the diet to avoid constipation.

For many people, the diverticula don't cause any problems, but some people may need emergency surgery because the diverticula become inflamed.

When the diverticula are not inflamed, symptoms tend to come and go. Episodic cramping, abdominal pain, bloating and excess wind are common.

These are often accompanied by a change in normal bowel patterns, with constipation or diarrhoea, or both, alternating.

Dietary advice to increase the amount of fibre is essential. Increasing fluid consumption, becoming more active and always responding to your body's bowel movement signals lessen the chance of constipation.

Antispasmodic medication, peppermint tea and painkillers are recommended for use when needed.

Infection in the diverticula, possibly caused by an impacted piece of faeces, is responsible for the inflammation that develops. When this happens - called diverticulitis - the pain is very severe and usually felt in the lower left side of the abdomen.

A person will often feel feverish and have nausea and vomiting. They may pass blood rectally.

Someone with diverticulitis may be treated at home with painkillers, antibiotics, laxatives and dietary advice. But diverticulitis is often severe, and can need hospital treatment with antibiotics and fluids given through a drip.

In some cases, the bowel may perforate, become obstructed or bleed heavily. When this happens, the situation becomes an emergency and an operation may be needed.

This article was last medically reviewed by Dr Rob Hicks in January 2008