Diverticular disease

Diverticular disease is extremely common. Between one-third and half of the population of Western Europe and North America will get diverticula in the colon during their lifetime.

The likelihood of having the condition increases as we get older. Less than one person in 20 has the condition before the age of 40, rising to a quarter by 60 years of age, and two-thirds by the age of 85. Most people with diverticula suffer no symptoms or complications whatsoever. Indeed, as many as three people in four with diverticula are quite unaware they have the condition. It is just not clear why a minority end up being unwell.

What is diverticular disease?

Diverticulum is a Latin term meaning a side-branch or pouch. When such pouches stick outwards from the wall of the large intestine (also known as the colon) we call this diverticular disease. It can be hard to understand how these pouches occur but try to imagine your large intestine as being similar to a bicycle tyre with a soft easily stretched inner tube and a tough outer tube. If a hole is made in the outer tube, when the inner tube inflates, it squeezes out through the hole. Like the tyre, our intestine has a soft flexible lining surrounded by a tougher outer tube of muscle. There may not be a hole in the outer tube as such but where there is a weakness in the muscle, the inner layer can push through it to form the pouch that we call a diverticulum. The term diverticula is used when there is more than one diverticulum in the bowel.


What is the difference between diverticular disease and diverticulitis?

The medical terms can seem a little confusing. If diverticular disease is so common yet causes no symptoms, is it fair to call it a disease? Some authorities call uncomplicated diverticular disease by the name diverticulosis. Diverticular disease is a term mainly used in people who develop symptoms. You may hear the term ‘diverticulitis’ which strictly means the condition that occurs when a single diverticulum or several diverticula become inflamed.

Where do diverticula occur in the intestine?

By far the most common site for diverticula is in the lower part of the colon. Diverticula do occasionally occur in the small intestine and some other parts of our insides but here we focus just on those that occur in the colon.

Symptoms of diverticular disease

If you have diverticular disease, your symptoms may include:

  • lower abdominal (tummy) pain and cramping
  • bloating
  • changes to your bowel movements, such as constipation or diarrhoea

The symptoms of diverticulitis may be more severe and include:

  • constant lower abdominal pain on the left-hand side
  • a frequent need to urinate
  • a fever (high temperature) and chills
  • feeling sick or vomiting
  • a loss of appetite

Patients often find that their symptoms begin suddenly and gradually get worse over a few days.Asian people sometimes develop diverticula in a different part of their bowel, and pain from diverticulae may occur on the right-hand side of the abdomen. This is thought to be hereditary.However, these symptoms may also be caused by problems other than diverticular disease. If you have any of these symptoms, see your GP for advice.

Causes of diverticular disease

Although the reason isn’t clear, it is thought that lifestyle and diet play a part in causing diverticular disease. If you don’t have enough fibre in your diet, your faeces may become small, pellet-like and hard. This makes it more difficult for you to empty your bowel and your bowel has to contract more vigorously to expel them. This creates additional pressure inside your bowel and causes weak points to develop in the muscle. Diverticula can then form and push through these weak points. Diverticular disease is rare in vegetarians and in people who eat enough fibre in their diet.

Diagnosis of diverticular disease

Diverticular disease is sometimes difficult to diagnose because your symptoms may also be similar to those of other conditions, such as irritable bowel syndrome (IBS).

Patients with bowel symptoms may require one or more of the following tests to diagnose the condition.

  • A blood test to check the level of the white blood cell count. A high level of white blood cells can be a sign of  infection and usually occurs with diverticulitis.
  • A colonoscopy is a test that allows your doctor to look inside the colon
  • A CT scan uses X-rays to make a three-dimensional image of the abdomen. 

Treatment of diverticular disease

Treatment of diverticular disease depends on the severity of symptoms :

  • Pain relief : paracetamol can often help relieve pain. Ibuprofen should be avoided if possible as this can irritable the lining of the stomach and increase the risk of internal bleeding.
  • Laxatives: a bulk-forming laxative such as fybogel is often helpful if there is constipation. Bulk-forming laxatives increase the amount of faeces and soften them, making it easier to empty the bowels.
  • Antibiotics: if there are symptoms and signs suggestive of diverticulitis, then antibiotics are often prescribed.

Complications of diverticular disease

Complications are uncommon but may include infection, obstruction, bleeding and perforation. Infection may lead to the formation of pus collections commonly known as an abscess which requires surgical drainage. Infection may also cause bowel tissue to join together or to neighbouring surfaces to form an abnormal passageway known as a fistula which subsequently requires surgical intervention.

What should I eat?

Keeping the stools relatively soft and bulky may reduce the likelihood of more diverticula developing and may reduce the risk that hard pellets of faeces lodge within the pouches. In principle a diet high in plant fibre achieves both aims. Try to eat a mixture of high fibre foods. Fruit, vegetables, nuts, wholemeal bread and pasta, wholegrain cereals and brown rice are all good sources of fibre. Aim to have at least one high fibre food with each meal and try to have five portions of fruit or vegetables each day, but avoid a very high fibre diet if this seems to make things worse. Drink at least two litres (eight to ten cups) of fluid every day. 

People with symptoms from diverticular disease respond differently to fibre in the diet. One person may be helped by increasing the amount of plant fibre in the diet, another may feel that their symptoms become worse. The type of fibre one eats may usefully be varied. Some people find that it helps to take fibre in the form of fruit and vegetables (soluble fibre) rather than that in cereals and grains (insoluble). This is because insoluble fibre may cause more bloating and pain. Bran aggravates symptoms for some people and is not routinely recommended. Avoiding large or fatty portions of food is a common sense measure if symptoms are worse after meals. It is not possible to make rules about diet which suit everyone - an element of trial and error in what we eat is often helpful in finding what fibre suits us best.