Diverticular disease and diverticulitis

Your health experts: Mrs Sara Badvie, Consultant Laparoscopic, Colorectal and General Surgeon and Lizzie Rogers, Bupa Clinics GP and Lead Physician
Content editor review by Victoria Goldman, April 2021
Next review due April 2024

Diverticular disease is a condition where small pouches (called diverticula) form in the lining of your bowel and push out through your bowel wall. They may cause symptoms, such as pain in your tummy or a change in bowel habits.

If you have diverticulitis, your diverticula get swollen or infected. You may get a high temperature and feel very unwell. 

What is diverticular disease?

Lots of people have diverticula in their bowel without realising it. You may have just one or two diverticula or hundreds of them. These may be tiny or over 2cm wide. You’re more likely to get diverticula as you get older and the walls of your bowel get weaker.

There are three different ways your diverticula can affect you.


This is when your diverticula don’t cause any symptoms. Nearly one in 10 people over 45 have diverticulosis. This may increase to around eight in 10 people by the age of 85.

Diverticular disease

This is when your diverticula cause symptoms such as pain in your tummy. Around two or three in every 10 people with diverticulosis will get diverticular disease.


This is if your diverticula get inflamed (red and swollen) or infected. Up to two or three in every 10 people with diverticulosis will get diverticulitis.

Symptoms of diverticular disease

If you have diverticular disease, you may:

  • have pain in your tummy that comes and goes – this may start when you’re eating and get better after you poo or pass wind (fart)
  • feel bloated
  • have constipation or diarrhoea or a general change in your bowel habits
  • notice blood or mucus coming out of your rectum (back passage)

You may have some bleeding if blood vessels inside your diverticula get weaker and burst. This doesn’t cause any pain or last long. You may get stomach cramps first.

Most people have diverticula on the left side of their bowel. So, if you have diverticular disease, this is usually where your pain is. But you can also get pain on your right side, particularly if you’re of Asian heritage.

Once you’ve had symptoms of diverticular disease, you may get them again. If your symptoms don’t go away or you have any rectal bleeding, contact your GP.

Symptoms of diverticulitis

If you have diverticulitis, you usually feel very unwell. Your symptoms may include:

  • constant bad pain in your tummy, usually low down
  • a high temperature (fever)
  • feeling sick or being sick
  • not feeling hungry
  • finding it hard or sore to pee or needing to pee regularly
  • having a faster heart rate than normal

If you have any of these symptoms, contact your GP.

Causes of diverticular disease

Doctors don’t know exactly why some people have diverticula and others don’t. They also don’t know exactly why some people then get diverticular disease. But it’s thought that your diet, lifestyle and even your family history may be important.

You may be more likely to get diverticular disease if you eat a low-fibre diet. Fibre helps your digestive system work smoothly. There’s lots of fibre in fruits and vegetables, wholegrains, nuts and seeds. If you don’t eat much fibre, your poo may be hard and more difficult to pass. This creates more pressure in your bowel, so diverticula form. Vegetarians and people who eat a high-fibre diet may be less likely to get diverticulosis and diverticular disease.

You may also be more likely to get diverticular disease if you:

Diagnosis of diverticular disease

If you don’t have any symptoms, diverticulosis is often spotted when you’re having other tests, such as a colonoscopy as part of bowel screening.

If you have symptoms, your GP will ask you about them. They may feel your tummy and inside your rectum for any tenderness or lumps. They may also ask about your medical history, diet and bowel movements.

Diverticular disease can be hard to diagnose because its symptoms are similar to other conditions. These include:

In women, symptoms such as tummy pain and nausea may be signs of an ovarian cyst or ectopic pregnancy.

Your GP may refer you to see a specialist in bowel conditions (a colorectal surgeon or gastroenterologist). You may need to have one or more of the following tests.

  • A blood test. This can check if bleeding has caused anaemia. It can also show if you have signs of diverticulitis such as inflammation or if you have an infection.
  • Computer tomography (CT) scan of your tummy and pelvis. This can show if you’ve got diverticulitis and any complications.
  • Ultrasound of your tummy and pelvis. You may have this if you can’t have a CT scan.
  • A colonoscopy or sigmoidoscopy. Your doctor will look inside your large bowel to see if you have any diverticula. This will also help to rule out other conditions and find where any bleeding is coming from.
  • An X-ray of your tummy. This can check for complications such as a hole (perforation) in your bowel.
  • A laparoscopy. This involves putting a narrow, tube-like telescopic camera (laparoscope) into your tummy through a small cut. It may be recommended if the cause if your symptoms still isn’t clear.

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How to help yourself

If you have diverticular disease but your symptoms aren’t very bad, there are lots of things you can do to ease them yourself.

Eat more fibre

Adding more fibre to your diet may help your symptoms. It can make your bowel movements more regular and encourage healthy bacteria to grow in your tummy and bowel.

To get more fibre, eat a healthy balanced diet, rich in wholegrains, fruits and vegetables. You should aim to eat around 30g of fibre a day. There’s roughly 5g of fibre in a jacket potato, 2g in an average apple or banana, and 5g in two slices of wholemeal bread.

It’s best to gradually increase how much fibre you eat. If you suddenly increase the fibre in your diet, you may feel bloated and have more wind than usual.

Your symptoms may seem better after a few days, but it may take as long as a month for you to feel a difference. For more information, see our FAQ: I have diverticular disease. Should I avoid eating certain foods?

Drink more fluids

Drink plenty of fluids if you’re eating more fibre because fibre absorbs water. Most adults should drink around 1.5 to 2 litres of fluid every day. This is roughly the same as six to eight mugs of water.

Change your lifestyle

You may also ease your symptoms if you:

  • eat regular meals
  • stop smoking
  • lose weight if you’re overweight
  • don’t take medicines that may cause constipation – for example, painkillers containing opioids

Treatment of diverticular disease

Your treatment will depend on how bad your symptoms are and how likely you are to get complications.


Your GP may give you a bulk-forming laxative if you can’t eat a high-fibre diet or have ongoing diarrhoea or constipation. This will make your poo softer and bulkier, which triggers your bowel muscles to contract. This makes it easier for your poo to pass out of your bowel when you go to the toilet.

Your GP may also suggest you take paracetamol to ease any pain. It’s best not to take non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and aspirin because these may make your diverticula bleed.

If you have bad tummy cramps, your GP may prescribe a medicine called an antispasmodic to stop your bowel contracting.

Always read the patient information leaflet that comes with your medicine. If you have any questions, ask your pharmacist or GP for advice.

Treatment of diverticulitis


If you have diverticulitis but only a little inflammation or you have an infection, your GP may prescribe antibiotics that you can take at home. You’ll usually take the antibiotics for seven to 10 days.

While you’re taking antibiotics for diverticulitis you may need to stick to a simple low-fibre diet, eating foods such as white rice. Or your doctor may recommend that you don’t eat anything for a few days and just have clear drinks (especially water) until you feel better. You can then gradually eat more solid foods again.

Always read the patient information leaflet that comes with your medicine. If you have any questions, ask your pharmacist or GP for advice.

Your doctor will probably want to see you again after a couple of days to check your symptoms are getting better.

Hospital treatment

If you have diverticulitis, you may need to go into hospital if:

  • your symptoms are really bad
  • your symptoms don’t get better after two days of treating them at home
  • you have a weak immune system
  • paracetamol doesn’t ease your pain
  • you’re not keeping antibiotic tablets down
  • you get a complication such as heavy rectal bleeding
  • you’re likely to get dehydrated and can’t drink enough fluids at home
  • you have other conditions such as diabetes or cirrhosis

You’ll be given antibiotics and fluids through a drip that’s inserted into a vein in your hand or arm. You may be told to eat only certain foods to ‘rest’ your bowels.

Procedures and surgery

Most people with diverticular disease don’t need surgery and can treat their symptoms at home with the help of their GP. But if you have diverticulitis, you may get some complications. Some of these complications may need to be treated with surgery or a surgical procedure.

If you have any of these complications, contact a doctor straightaway.


A pus-filled lump called an abscess may form on the outside wall of your bowel. This can cause pain in your pelvic area and around your anus (back passage).

If you have an abscess, you may need a procedure to drain it. Under local anaesthesia, a thin needle and catheter are placed into the abscess through your skin. These are then guided into the right place using pictures from a computer tomography (CT) scan or ultrasound scan.

Severe infection

If your diverticula are badly infected, they can sometimes burst and cause an infection in your tummy. This is called peritonitis.

If you have a bad infection, you’ll need emergency surgery to drain any pus and clean the inside of your tummy. This is usually done with a laparoscopy or laparoscopic surgery, through small cuts in your tummy.

Fistulas and blockages

If an abscess bursts into one of your organs, such as your bladder, you may get a fistula. A fistula is a passageway that joins two parts of your body together that aren’t normally connected. Signs of a fistula depend on where it is. You may keep getting urine infections or, in women, vaginal discharge.

If your diverticula keep getting inflamed, your bowel may get narrower or get blocked. You may have constipation, trapped wind, bad tummy pain and a swollen tummy. You may also feel sick or be sick.

You may need bowel resection surgery to remove the damaged or blocked part of your bowel or to correct a fistula. If possible, your surgeon will remove the affected part of your bowel and join the remaining healthy parts together. But if they can’t do this safely, maybe because you have a bad infection, you’ll need to have stoma surgery.

Prevention of diverticular disease

Lots of things may make you more likely to get diverticular disease. You can’t avoid some of these things, such as getting older or having certain other conditions. But making certain changes to your lifestyle may help to reduce your chance of getting diverticular disease.

Symptoms of diverticular disease include tummy pain, feeling bloated, constipation and/or blood coming out of your rectum (back passage). Pain is often felt on the left side of your tummy, but it can happen on the right. If you have any rectal bleeding, see your GP. For more information, see our section on symptoms.

You don’t need to avoid any specific foods. But try to avoid any foods or drinks that could make you constipated, such as coffee, tea or alcohol. Dairy products may also make you constipated, but don’t cut these out of your diet without speaking to a dietitian first. If you notice specific foods are triggering your symptoms, you should also discuss this with your doctor.

Doctors used to recommend that you shouldn’t eat nuts, seeds, fruit skins, corn or popcorn if you have diverticular disease. This is because they thought little bits of these foods could get stuck in your diverticula pouches and cause complications. But research shows that these foods don’t make diverticular disease worse.

Most people who get diverticulitis don’t get it again. You may still notice some tummy pain after your treatment has finished. If your symptoms change or get worse, it’s important to tell your doctor.

Of those people who do get diverticulitis again, one in two will experience it within a year of their first episode. Around nine in ten people who get it again will get it in the first five years after their first episode. Eating a high-fibre diet will help to keep your diverticular disease under control.

If you keep getting diverticulitis, you may need to have surgery.

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This information was published by Bupa's Health Content Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals and deemed accurate on the date of review. Photos are only for illustrative purposes and do not reflect every presentation of a condition.

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