Diverticulosis Diverticulitis

Overview

Diverticulosis means small pouches have formed in the wall of your bowel (usually the lower part, called the colon). These pouches are like small bulges pushing out through weak spots. Most people who have them never know, because they cause no trouble. Diverticulitis is when one or more of these pouches becomes inflamed or infected. It is the 'itis' part that makes you feel unwell — it can cause belly pain and fever and needs medical care. So: diverticulosis is having the pouches; diverticulitis is when a pouch gets sore and swollen.

Yes. Diverticulosis is one of the most common bowel findings in adults over 50. In countries where people eat less fibre, it becomes more common with age. Around one in three adults over 60 and about half of people over 80 have these pouches. Diverticulitis is much less common — most people with pouches never get it.

It mostly affects adults over 40, and the chance rises as you get older. It is more common in people who eat a low-fibre diet and in people who are overweight or smoke. It can happen in younger adults too, though this is less usual. Children rarely get it.

Symptoms

Common symptoms

• Diverticulosis: usually no symptoms at all — it is often found by chance during tests for something else.
• Some people with pouches notice bloating, mild cramping, or changes in bowel habits, though this is not always caused by the pouches.
• Diverticulitis: pain, often on the lower left side of the belly, that may be steady and sore to touch.
• Fever, feeling hot and shivery, or generally feeling unwell.
• Feeling sick, being sick, or losing your appetite.
• Constipation or diarrhoea, or needing to pass wind more than usual.
• A tender or bloated belly.

Symptoms in children

• Diverticular disease is rare in children, so other causes of belly pain are much more likely.
• When it does happen, children may complain of vague tummy pain, and may have fever or vomiting.
• Children with long-term conditions such as cystic fibrosis have a higher chance, so doctors may think of it in that group.
• Any child with severe or lasting belly pain should be seen by a doctor.

Symptoms in older adults

• Older adults may have less obvious pain and may not get a high fever, even when they are quite unwell.
• New confusion, drowsiness, or a sudden drop in energy can be a warning sign in frail older people.
• Dehydration can happen faster, especially if there is vomiting or diarrhoea.
• Because serious problems are more likely with age, it is safer to get checked early rather than wait.

Causes

Main causes

• Pouches form where blood vessels pass through the muscle wall of the bowel, making a natural weak spot.
• Pressure inside the bowel rises when stools are hard and you have to strain — this pushes the inner lining out through those weak spots.
• A diet low in fibre over many years is a major reason stools become hard and pressure builds up.
• Diverticulitis happens when a pouch becomes irritated, inflamed, or infected — sometimes a tiny hole or a bit of trapped stool starts the problem.

Risk factors

• Getting older — the bowel wall weakens over time.
• A long-term diet low in fibre and low in fruit and vegetables.
• Being overweight.
• Smoking.
• Not being very physically active.
• Some medicines can raise the risk, such as certain painkillers and steroid tablets — ask your doctor or pharmacist about your own medicines.
• A family history of diverticular disease.
• Long-term constipation and straining.

When to see a doctor

See a doctor urgently if:

• Belly pain with a fever or chills.
• Pain that is severe, one-sided, and not easing.
• Vomiting so you cannot keep fluids down.
• Blood in your stool or bleeding from your bottom.
• You feel very unwell, dizzy, or confused.

Book a routine appointment if:

• A change in your bowel habits that lasts more than a few weeks.
• Bloating or cramping that keeps coming back.
• You have been told you have diverticulosis and want advice on diet and fibre.
• Mild, short-lived tummy pain that settles but worries you.

Diagnosis

Your doctor will start by asking about your symptoms, your bowel habits, and your past health, then examine your tummy by gently pressing it. Diverticulosis is often found by chance when someone has a colonoscopy (a camera test of the bowel) or a scan for another reason. If your doctor thinks you may have diverticulitis, they will check for fever, tenderness, and signs of infection, and may arrange blood tests or a scan. If you have had inflammation, you may be offered a colonoscopy later on, usually a few weeks after you have recovered, to check the bowel is healthy.

Tests that may be done

• A physical examination of your tummy.
• Blood tests to look for signs of infection or inflammation.
• A stool sample to rule out an infection that causes similar symptoms.
• A CT scan — a detailed picture of the bowel that shows inflammation or problems such as an abscess.
• An ultrasound scan, which is sometimes used instead of a CT scan.
• A colonoscopy (camera test) — usually done after the inflammation has settled, not during a flare-up.

What to expect at your appointment

Most of the tests are quick and painless. A blood test takes a minute, and a CT scan is done lying still on a bed that slides through a ring-shaped scanner. A colonoscopy means a day of bowel preparation and light sedation, so you will need someone to take you home. Your doctor will explain what each test is for so you can decide together what feels right. If you feel anxious, it is fine to say so and ask for extra support.

Treatment

Diverticulosis itself usually needs no treatment — just a healthy, high-fibre diet. Diverticulitis is treated depending on how mild or severe it is. Many mild cases settle at home within a few days with rest, fluids, and pain relief, plus a check-in with your doctor. More serious cases need hospital care, where you may be given fluids through a drip and watched closely. Your doctor will decide what is right for you.

Self-care at home

• Rest and give your tummy time to settle.
• Sip plenty of fluids, such as water and clear soups, so you do not get dehydrated.
• During a painful flare, your doctor may suggest a short period of low-fibre or liquid foods, then slowly adding fibre back.
• Use a warm pack or hot water bottle on your tummy for comfort.
• Take simple pain relief only as advised by your doctor or pharmacist — avoid guessing, and check which painkillers are safe for you.
• Note your symptoms — when they started, what makes them better or worse — so you can tell your doctor clearly.
• Once you feel better, build fibre back into your diet slowly so your bowel is not shocked.

Medical treatments

Treatment depends on how unwell you are. For a mild flare, your doctor may suggest rest, fluids, and pain relief at home, with a follow-up plan. In some cases they may prescribe antibiotics (medicines that fight infection) — guidance now is that not everyone needs them, so your doctor will judge what suits you. If you are more unwell, you may be referred to hospital for fluids through a drip, stronger pain relief, and monitoring. If a collection of pus (an abscess) forms, a doctor may drain it using a thin needle guided by a scan. Your healthcare team will explain each option and why they are recommending it.

When is surgery considered?

Surgery is needed only in a small number of cases. It may be considered if you have repeated, troublesome attacks, or if a serious complication happens — such as a hole in the bowel, a blockage, a narrow or scarred section, an abscess that cannot be drained, or an abnormal connection between the bowel and another organ. Surgery may be done as keyhole (small cuts) or open surgery, and the unhealthy section of bowel is usually removed. Many people recover well, and your surgical team will talk through the risks and benefits with you beforehand.

Living with this condition

Most people with diverticulosis live completely normally and rarely think about it. If you have had diverticulitis, you may feel anxious about it coming back, and it helps to know that many people have one episode and no more. Keep an eye on how your body responds to different foods, and remember that a sudden bad flare with fever is your signal to seek medical help rather than push through.

Lifestyle tips

• Eat a varied diet with plenty of fibre — wholegrains, fruit, vegetables, beans, and lentils.
• Increase fibre slowly over a few weeks so your gut can adjust.
• Drink enough water each day, especially as you add more fibre.
• Stay active — regular walking or whatever movement you enjoy helps your bowel keep moving.
• Try not to strain or rush on the toilet; give yourself time and don't ignore the urge to go.
• If you smoke, getting support to stop is one of the best things you can do for your bowel and your overall health.
• Aim for a healthy weight, and ask your doctor if you'd like help with this.

Diet and exercise

Fibre is the key. It softens your stools so your bowel doesn't have to push so hard, which lowers the pressure that causes pouches. Aim to build up gradually — sudden big jumps in fibre can cause wind and bloating. Good sources include wholemeal bread and pasta, oats, brown rice, nuts, seeds, fruit with the skin on, and vegetables. Water matters as much as fibre; without enough fluid, extra fibre can make constipation worse. There is no need to avoid seeds, nuts, or popcorn — older advice to cut them out is no longer supported. Exercise helps too: moving your body helps your gut move, and it supports a healthy weight.

Mental health and emotional wellbeing

Bowel problems can affect how you feel about yourself and your life. Some people worry about pain returning, feel embarrassed about wind or sudden toilet needs, or plan their day around where the nearest toilet is. That is very common and understandable. It can also affect sleep, mood, and confidence. Talking to someone — your doctor, a nurse, a counsellor, or a trusted friend — really does help. If low mood, worry, or stress is building up, please reach out for support rather than coping alone.

Prevention

You cannot fully prevent diverticulosis, especially as it is linked to ageing. But you can lower your chance of problems and of flare-ups. The most helpful steps are eating plenty of fibre, drinking enough water, staying active, not smoking, and keeping to a healthy weight. If you have already had diverticulitis, these habits still matter — they support your bowel and your overall health.

Vaccines

There is no vaccine for diverticular disease. Staying up to date with routine vaccinations recommended for your age and health is still a good idea, as it helps you stay well overall.

Screening programmes

There is no routine screening programme just for diverticular disease. If you are offered bowel cancer screening for your age group, it is still important to take part — it checks for other conditions and is not related to diverticulosis. If you have had diverticulitis, your doctor may arrange a colonoscopy afterwards to check the bowel is healthy. Ask your doctor which screening applies to you.

Complications

If left untreated

• An abscess — a pocket of pus that forms near the inflamed pouch.
• A perforation — a small hole in the bowel, which lets bowel contents leak and causes serious infection.
• Peritonitis — inflammation of the lining of the tummy, which is a medical emergency.
• A stricture — a narrow, scarred part of the bowel that can cause blockages.
• A fistula — an abnormal tunnel between the bowel and another organ, such as the bladder.
• Bleeding from a pouch, which can appear as blood in your stool.
• Repeated attacks that leave you feeling tired and unwell.
• In serious cases, sepsis — a whole-body reaction to infection that needs emergency treatment.

Long-term outlook

The outlook is good for most people. The great majority of people with diverticulosis never have any problems at all. Even if you have had diverticulitis, most people recover fully and many have only one episode. With a high-fibre diet, enough fluids, and regular movement, you are doing the most useful things to keep your bowel healthy. If you notice warning signs like fever with tummy pain, get help early — that is what keeps small problems from becoming big ones. And if you feel worried or low, please tell your doctor.

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