What are diverticulosis, diverticular disease and diverticulitis?

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

The following table shows what the different terms mean:

Diverticulosis becomes more common with age. It affects one in 10 people aged over 45 years, and about 66% of people over 70 years of age.

What are the symptoms?

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
• irregular bowel habits — alternating episodes of constipation and diarrhoea

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

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

Diverticulitis

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

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

These symptoms may be mild to 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.

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
• a fever
• start vomiting
• feel very unwell
• blood in your poo

How are these conditions diagnosed?

Diverticulosis and diverticular disease

Diverticulosis is usually diagnosed during bowel cancer screening or screening 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 or if you have symptoms of diverticular disease.

Diverticulitis

To diagnose diverticulitis, your doctor will talk to 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

How is diverticular disease treated?

Diverticular disease

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

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. 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 your vein. You may also need strong pain relievers. People who do not improve with treatment or who develop complications may require surgery.

Can diverticular disease be prevented?

A high-fibre diet helps to prevent constipation and may help prevent more diverticula (pouches) from forming. It can also help ease the symptoms of diverticular disease.

Exercising regularly and drinking enough water (up to 8 cups a day) are also recommended.

Complications of diverticular disease

Complications of diverticular disease and diverticulitis can include:

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

These complications need urgent treatment.

Resources and support

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.