As people age, it’s common for them to develop bulges in the lining of the colon (the large bowel). These are called diverticula (see picture). About 1 or 2 out of every 10 people aged 45 or older have them. Diverticula can form in other parts of the digestive system too.

Usually, diverticula don’t cause any symptoms. However, in about 1 in 4 people, they cause symptoms such as abdominal pain, feeling bloated, and constipation or diarrhoea.

• Diverticulosis: diverticula that aren’t causing symptoms.
• Diverticular disease: diverticula that are causing symptoms.
• Diverticulitis: infected and inflamed diverticula.

You may have heard that you’re more likely to develop diverticula if you have ADPKD. This may be true if you have ADPKD and you also have kidney failure (i.e. you’re having dialysis or have had a kidney transplant).

However, people with ADPKD who have functioning kidneys are thought to have the same chance of developing diverticular disease as people without ADPKD. In the UK, about half of all people aged 50 years have diverticula.

Like the general population, people with ADPKD are only tested for diverticular disease if they have symptoms. Screening is not routinely available. If you have tests for other bowel problems, these may spot diverticula. If you have symptoms such as bloating, constipation or diarrhoea, your GP may refer you for tests to find the cause. We explain these tests later.

Usually, diverticula don’t cause symptoms or need treatment. However, if you have ADPKD and kidney failure, you could be more likely to get symptoms and complications of diverticular disease. Complications can include infections (called diverticulitis), an abscess in the abdomen, sudden bleeding, or a tear in your bowel, which would need treatment. In a study, 1 in 5 people with ADPKD who had received a kidney transplant developed a diverticulitis infection over a 12-year period.

Your doctor can explain symptoms to look out for and ways to reduce your risk of complications if you have diverticula.

If you need dialysis and have diverticular disease, your kidney specialist might suggest haemodialysis rather than peritoneal dialysis. Haemodialysis uses a machine to filter the blood, whereas peritoneal dialysis uses fluid placed in your abdomen. It is thought that using peritoneal dialysis if you have diverticular disease might increase your chance of developing fluid on the lung or having a hernia. Many people with diverticula can still have peritoneal dialysis though. The decision of which type of dialysis to have is based on many factors, including what you would find most convenient.

Diverticula can be found using:

• a computed tomography (CT) scan, which uses X-rays to make images of the inside of your abdomen.
• a colonoscopy, which uses a camera in a thin tube to look inside the bowel.

There is no ‘simple fix’ for diverticular disease, but changes to diet and medications can help.

Treatment depends on symptoms:

• If you have diverticular disease, your doctor may recommend a diet high in fibre, e.g. whole grains, fruit and vegetables. This can reduce pain, bloating and the chance of getting a diverticulosis infection. You can find out more about this diet at NHS Inform. Medications can reduce pain and treat constipation.
• If you have a diverticulosis infection, your doctor may recommend having only clear fluids (and no solid food) for 2—3 days to allow your bowel to settle down. You can then reintroduce solid food gradually as you start to feel better. You may need antibiotics. If you’re becoming very dehydrated, you may need fluid through a drip at hospital. Less commonly, you may need surgery.

It is not known why diverticular disease is more common in people with ADPKD and kidney failure. One suggestion is that the gene faults that cause ADPKD can also cause the muscle of the bowel wall to be weaker. Another idea is that the ‘glue’ that holds cells together (the extracellular matrix) is abnormal in the bowel of people with ADPKD].

Click on the links below for more information from the PKD Charity on related topics:

• ADPKD progression
• Symptoms of ADPKD

Click on the websites below to get information and support from other organizations:

• NHS Inform has information on the diverticular disease and diverticulitis including diet for treatment of flares (low fibre) and for prevention of problems (high fibre).
• NHS Choices has information on diverticular disease and diverticulitis, CT scans, colonoscopy and dialysis.
• Guts UK has information on diverticular disease and other bowel conditions (email: ; 020 7486 0341).
• 'Coping with Diverticulitis' - book by Peter Cartwright with useful information and advice (external link to Amazon books UK)