What are diverticulosis, diverticular disease and diverticulitis?

Diverticulosis, diverticular disease and diverticulitis are all part of the same condition that can affect your large bowel.

The following table shows what the different terms mean:

Diverticulosis becomes more common with age. It affects:

• less than 1 in 10 people aged under 40 years
• 1 in 2 people aged over 80 years

Vegetarians are less likely to have diverticular disease than people who eat meat.

What are the symptoms?

Always see your doctor if you have any bleeding from your bowel or back passage.

Diverticulosis

Most people with diverticulosis do not have any discomfort or symptoms.

Diverticular disease

Symptoms of diverticular disease can include:

• mild cramps, or lower abdominal (tummy) pain that comes and goes
• bloating
• irregular bowel habits — alternating episodes of constipation and diarrhoea

Sometimes diverticular disease causes blood in your stool (poo). This is from diverticular (pouch) bleeding.

Diverticulitis

The most common symptom of diverticulitis is pain, usually in the lower, left-hand side of your abdomen. Other symptoms of diverticulitis may include:

• fever
• a change in your bowel habits, such as constipation or diarrhoea
• nausea
• vomiting

These symptoms may be mild or severe.

What causes diverticulosis and diverticulitis?

Diverticulosis is linked to a low-fibre diet.

When you have a low-fibre diet and constipation, you must strain to pass stools (do a poo). The pressure from straining can cause weak spots in your bowel to bulge out. These form pouches or pockets called 'diverticula'.

Other factors that can increase the risk of diverticulosis and diverticular disease are:

• a diet high in red meat and salt
• reduced physical activity
• obesity
• smoking

Diverticulitis is when a diverticulum (pouch) becomes inflamed or infected. This can be caused by bacteria being trapped inside one of the bowel pockets.

When should I see my doctor?

See your doctor if you have:

• cramps or lower abdominal (tummy) pain
• irregular bowel habits — alternating episodes of constipation and diarrhoea
• blood in your stool (poo)

See your doctor immediately if you:

• have severe abdominal pain
• have a fever
• start vomiting
• feel very unwell
• have blood or mucus in your poo

How are diverticulosis, diverticular disease and diverticulitis diagnosed?

Diverticulosis and diverticular disease

Diverticulosis is usually diagnosed during bowel cancer screening or testing for gut problems.

A colonoscopy is a type of test that can detect diverticulosis. Your doctor may recommend you have a colonoscopy after an episode of diverticulitis. It may also be recommended if you have symptoms of diverticular disease.

Diverticulitis

To diagnose diverticulitis, your doctor will talk with you about your symptoms and examine you.

Your doctor may recommend tests to confirm your diagnosis. These may include:

• blood tests
• a CT scan of your abdomen

Your doctor may also refer you to a gastroenterologist (doctor who specialises in conditions affecting the gastrointestinal system).

How is diverticular disease treated?

Your doctor may recommend a high-fibre diet to reduce your symptoms of diverticular disease and prevent complications.

They may also recommend you increase the amount of fluids you drink. About 8 cups of water each day is recommended.

Diverticulitis

If you have mild diverticulitis, you may be treated at home. Treatment includes bowel rest. This involves having a low-fibre or a fluid-only diet until your symptoms improve.

Sometimes your doctor may prescribe antibiotics. You can also take mild pain-relief medicines if needed.

If you have severe diverticulitis, you may need to be admitted into hospital. Treatment includes antibiotics and fluids. These may be given through a drip into one of your veins. You may also need strong pain-relief medicines.

People who do not improve with treatment or who develop complications may need surgery.

Can diverticular disease be prevented?

You can help prevent diverticular disease by:

• eating a high-fibre diet that contains plenty of fruits and vegetables
• reducing the amount of red meat and salt in your diet
• getting regular physical activity
• maintaining a healthy weight

If you have diverticulosis, you can also help lower your risk of diverticulitis and other complications by:

• eating a high-fibre diet to maintain soft stools
• maintaining a healthy weight
• quitting smoking

Complications of diverticular disease

Complications of diverticular disease and diverticulitis can include:

• bleeding from your bowel
• bowel perforation (a tear in the wall of your bowel)
• an abscess (collection of pus)
• bowel obstruction (blockage) due to scarring
• a fistula — an abnormal connection forming between the bowel pouches and other organs in your abdomen, such as your bladder
• sepsis

These complications need urgent treatment.

If you've had complications of diverticular disease or diverticulitis, your doctor may recommend tests to check for bowel cancer.

Resources and support

The Gastroenterological Society of Australia (GESA) has patient information on gastrointestinal conditions, including diverticular disease.

You can find a dietitian or information on diet for diverticular disease through Dietitians Australia.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.