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Overview of diverticular disease & diverticulitis

He puku hamuti kārawarawa

Diverticula are small pouches or bulges that form in the wall of your large bowel (your colon or large intestine). Diverticula is plural (more than one). One pouch is a diverticulum.

Diverticula do not always cause symptoms or problems. If you have them without any symptoms, it's called diverticulosis. It's a common condition among older people, affecting around 80% of people over 80 years old.

If you have diverticulosis with symptoms like cramps or bloating with diarrhoea or constipation, it's called diverticular disease.

Diverticulitis is when the diverticulum become inflamed or infected. This can cause symptoms such as lower tummy (abdominal) pain or bloating. An abscess may form, or the diverticulum may burst causing inflammation inside your whole tummy area (peritonitis). The inflammation can affect nearby organs such as the bladder or cause a narrowing of the bowel.

Bleeding from the small blood vessels at the neck of a diverticulum can happen. In some cases, it can be serious bleeding.


It's important to tell your general practice team about any bleeding from your bottom to have it checked and to rule out serious causes.

Causes of diverticular disease & diverticulitis

When you eat plenty of fibre-rich foods and drink plenty of fluids, your stools are more likely to be bulky and soft. This type of stool can easily be moved along your gut by gentle contractions of the muscles in your gut wall.

If you do not eat enough fibre-rich foods and drink plenty of fluids, you can become constipated as your stools become harder. To pass harder stools, your bowel has to contract more forcefully, putting pressure on weaker parts of your gut wall. This causes bulges in the gut wall called diverticula.

Symptoms of diverticular disease & diverticulitis

You might have diverticular without any symptoms. Sometimes, they're diagnosed after having a scan or colonoscopy.

If you have diverticular disease, you might feel occasional cramps or pain in your lower tummy. You'll feel it most on your left side and it may also cause some bloating feelings. Your stools may change and be looser (diarrhoea) or hard and small (constipated). Going to the toilet may help ease the pain or bloating.

Diverticulitis starts when some stool gets stuck in a diverticulum and causes an infection and inflammation. If this happens, you may feel more severe or constant tummy pain, constipation or diarrhoea, nausea (feeling sick), vomiting and fever.

You can get several complications if you've developed diverticulitis. These are uncommon but serious and will often need surgical treatment.

These include:

If any of these complications develop, you'll need to go to hospital and have a CT scan so that treatment can be arranged.

Treating diverticular disease & diverticulitis

Having a high-fibre diet and drinking plenty of fluids help to prevent diverticular disease. It keeps your stools (poo) soft and helps prevent constipation.

If you have diverticulitis without any complications, your treatment will usually involve:

You may need to see your general practice team during this time to make sure things are settling down. Your symptoms will generally go away within a week, but you may feel tired and a little sore for a couple of weeks. As you recover, you need to make sure that you're drinking plenty of fluids to reduce the chance of becoming constipated. You can gradually return to a high-fibre diet.

If there are any signs of complications, you'll be referred to the hospital for further investigations and treatment. This may involve antibiotics, pain relief and fluids given through a drip. It may also require other treatment such as draining an abscess and very occasionally, an operation.

If you have bleeding, you may need a colonoscopy to find the cause of your bleeding and rule out things like bowel cancer.

If you have recurring issues with diverticular disease or diverticulitis, you may need to be referred to the General Surgical Outpatient Clinic for review and further treatment as needed. This could include surgery.

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Written by HealthInfo clinical advisers. Last reviewed July 2022.


See also:

Bowel cancer

Irritable bowel syndrome (IBS)

Page reference: 539835

Review key: HIDIV-114745