Diverticulitis: your five-minute guide

19 October 2022

If you have bloating and abdominal pain, accompanied by diarrhoea, constipation, or both, it could be due to diverticula - pouches - in your gut becoming inflamed or infected and causing diverticulitis. It's a very common, if little known, condition.

But what are diverticula? And what makes them cause diverticulitis? Let's find out.

What is diverticulitis?

Diverticulitis is caused by diverticula: small protrusions or pouches that stick out of the wall of the large intestine or gut a bit like the bulge that is made by pushing your finger into the side of a plastic carrier bag.

If you have one or more of these pouches in your gut, the condition is called diverticulosis. And if the diverticula become inflamed or infected, the condition develops into diverticulitis.

If you go to see your GP due to bloating and abdominal pain that is found to be caused by diverticulitis, you may also be given a diagnosis of diverticular disease, a term that encompasses all conditions related to diverticula.

Did you know?

If you have just one of these pouches, it's called a diverticulum. Diverticula = more than one diverticulum.

What causes diverticula?

Your intestinal muscles have to work harder if they there is not enough fibre or water in your gut, and it is thought that the pressure this creates on the walls of the intestine is what causes diverticula to form.

If the diverticula become infected due to the bacteria passing through your gut, the resulting inflammation can cause diverticular disease.

It is thought an infection develops when a hard piece of stool or undigested food gets trapped in one of the pouches. This gives bacteria in the stool the chance to multiply and spread, triggering an infection.

What are the symptoms of diverticular disease?

Most people who develop diverticula have no symptoms, but if your diverticula become inflamed, they can cause pain and bloating in your lower abdomen or tummy.

If you have diverticulitis, you may also experience diarrhoea or constipation, and sometimes notice mucus or blood in your poo. The pain usually comes after a meal and may be alleviated by going to the toilet.

Other symptoms can include a high temperature and nausea or vomiting, all of which are potentially signs the infection is getting worse.

If you experience these symptoms or notice any unusual bleeding when you go to the loo, you should therefore contact your GP as soon as possible.

This is important as more severe infections can cause blockages, perforations or fistulas that could have serious implications for your health longer term.

Is it linked to IBS (Irritable Bowel Syndrome) or bowel cancer?

People with diverticular disease often experience some of the same symptoms as people with either IBS or bowel cancer; that's why it's important not to ignore your symptoms, particularly if they include bloody stools.

However, while some studies suggest that IBS is more common among people with diverticular disease, this connection is yet to be proven.

When it comes to bowel cancer, meanwhile, there is no long-term connection between the two conditions, but those with acute diverticulitis may be more susceptible to bowel cancer in the short term1. A colonoscopy is therefore a sensible precaution.

Who is most at risk?

The risk of developing diverticular disease increases once you hit 40, although symptoms are most likely to occur in the over 70s.

The diagnosis is also more common in people who have obesity or a high body mass index. Under 70s who eat plenty of fibre (25g a day) have a 40% lower chance of admission to hospital with complications of diverticular disease2.

Know your numbers

About half of all people in the UK have diverticula by the time they are 50. And nearly seven in 10 people have diverticula when they reach 80 years old3.

What treatments are available?

The usual treatment for the infection (diverticulitis) is antibiotics and plenty of fluids, plus paracetamol for the pain.

Your doctor may also suggest that you increase the fibre in your diet to help food move through your gut and cause less strain on the muscles in your intestine.

In more severe cases, you may also be advised to have a colonoscopy to investigate the extent of the condition. And depending on what this finds, you may then require a colectomy, which involves removing an affected part of the large intestine.

If the surgeon decides that the large intestine needs to be bypassed on a permanent or temporary basis, so that healing can take place, you will also require stoma surgery, in which a tube is inserted from your intestine to outside your body to collect your faeces in an external pouch or colostomy bag.

However, this is only necessary in very rare cases.

How can I reduce my chances of developing diverticular disease?

The best way to reduce your risk of developing diverticulitis is to follow a high fibre diet on a permanent basis.

You can do this by increasing your intake of foods such as vegetables, fruit, nuts, and wholegrain cereals.

For those with very severe symptoms, or who find it hard to change their diet, fibre supplements are also available on prescription or over the counter in a pharmacy.

What else do I need to know about diverticular disease?

Most people with diverticulitis recover completely. However, complications related to diverticular disease include:

  • Bleeding, which usually resolves itself but may require hospital treatment.
  • Pain when you pee, or a feeling of needing to urinate more often.
  • An abscess developing outside the intestine.

Potentially the most dangerous complication involves a pouch bursting open and spilling faecal matter directly into a person's bloodstream, which can cause death from sepsis - that's why it's important not to ignore symptoms such as abdominal pain and bloating!


About the author

Jessica Bown is a freelance writer and journalist.