Diverticular Disease and Diverticulitis

Diverticular disease and diverticulitis are related digestive conditions which affect the large intestine (colon). Small bulges develop on the lining of the intestine which become inflamed or infected.

Symptoms of diverticular disease include:
  • lower abdominal (tummy) pain
  • feeling bloated.
Symptoms of diverticulitis include:
  • more severe abdominal pain
  • high temperature (fever) of 38ºC (100.4ºF) or above.

Diverticula, diverticular disease and diverticulitis

Diverticula

Diverticula is the medical term used to describe the small bulges which stick out of the side of the large intestine (colon). Diverticula are common and associated with ageing. It is thought the pressure of hard stools (poo) passing through the large intestine that has become weakened with age, causes the bulges to form.
Schematic diagram showing diverticulitis of the sigmoid colon

It is estimated that half of people have diverticula by the time they are 50 years old, and 70% of people have them by the time they are 80 years old. The majority of people with diverticula will not have any symptoms; this is known as diverticulosis.


Diverticular disease

One in four people (25%) who develop diverticula will experience symptoms such as abdominal pain. Having symptoms associated with diverticula is known as diverticular disease.


Diverticulitis

Diverticulitis describes infection which occurs when bacteria become trapped inside one of the bulges, triggering more severe symptoms. Diverticulitis may lead to complications, such as an abscess inside the intestine.


Treating diverticular disease and diverticulitis

A high-fibre diet may often ease symptoms of diverticular disease, and paracetamol may be used to relieve pain. Other painkillers (e.g. aspirin or ibuprofen/ neurofen) are not recommended, as they can cause stomach upsets in people with diverticular disease.

Mild diverticulitis can usually be treated at home with antibiotics. More serious cases may need hospital treatment to prevent complications. Surgery to remove affected section of the intestine is sometimes recommended, if there is a risk of serious complications, although this is fairly rare.


Who is affected

Diverticular disease is one of the most common digestive conditions. There were about 80,000 hospital admissions due to diverticulitis in England every year. Both sexes are equally affected by diverticular disease and diverticulitis, although the condition is more likely to appear at a younger age (under 50) in men than in women.

Diverticular disease is often described as a ‘western disease’, because the rates are high in western European and North American countries, and low in African and Asian countries. Diet is thought to be the reason for this, and the fact that people in western countries tend to eat less fibre.


Causes of diverticular disease and diverticulitis 

In order to better understand the causes of diverticular disease and diverticulitis, it is useful to understand how the large intestine (also known as the colon) works.


The large intestine
The large intestine plays two important roles in digestion. It:
  • helps remove nutrients from food people eat
  • pushes undigested waste products down into the rectum (the end of the large bowel) and out of the anus (back passage), where they are expelled from the body as stools (poo) when peopl go to the toilet.
The structure of the large intestine is similar to that of a tyre. It consists of a flexible inside layer of tissue covered by a firmer, tougher layer of muscle.


Lack of fibre

Not eating enough fibre is thought to be a main reason why the small bulges (diverticula) which stick out of the side of the large intestine develop. Fibre makes the stools softer and larger, so less pressure is needed by the large intestine to push them out of the body. Eating low-fibre food produces small, hard stools. These are more difficult for the muscles of the large intestine to move, and will cause patients to strain.

The pressure of moving the hard, small pieces of stools through the large intestine creates weak spots in the outside layer of muscle. This allows the inner layer to squeeze through these weak spots, creating the diverticula. There is no clinical evidence to fully prove the link between fibre and diverticula, but the circumstantial evidence is compelling.

For example, in parts of the world where high-fibre diets are common (e.g. Africa and South Asia), cases of of diverticula and diverticular disease are almost non-existent. However, in western countries, where many people do not eat enough fibre, diverticula and diverticular disease are much more common.


Diverticular disease

It is not known why only one in four (25%) people with diverticula go on to have the symptoms of diverticular disease. However, factors that appear to increase a person's risk of developing diverticular disease include:
  • smoking
  • being overweight or obese
  • having a history of constipation
  • physical inactivity
  • use of the non-steroidal anti-inflammatory drugs (NSAIDs) type of painkillers (e.g. ibuprofen or naproxen).

Exactly how these lead to developing diverticular disease is still unclear.


Diverticulitis

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


Symptoms of diverticular disease and diverticulitis 

The most common symptom of diverticular disease is intermittent (stop-start) pain in the lower abdomen (stomach), usually in the lower left-hand side. The pain is often worse when people are eating, or shortly afterwards. Passing stools (poo) and breaking wind (flatulence) may help relieve the pain.

Other symptoms of diverticular disease include:
  • a change in the normal bowel habits (e.g. constipation or diarrhoea), or episodes of constipation which are followed by diarrhoea
  • bloating
  • bleeding from the rectum (back passage).

Diverticulitis

The main symptom of diverticulitis is a constant and severe pain. The pain usually starts below the belly button, before moving to the lower left-hand side of the abdomen. In Asian people, the pain may move to the lower right-hand side of the abdomen. This is because Asian people tend to develop diverticula in a different part of their colon. The reason for this is thought to be genetic (certain genes found in Asian people may change the natural course of the condition).
Besides severe stomach pain, other symptoms of diverticulitis include:
  • a high temperature (fever) of 38ºC (100.4ºF) or above
  • feeling sick (neusea)
  • being sick (vomiting)
  • constipation
  • bleeding from the rectum.

When to seek medical advice

Patients must contact their doctor/ GP as soon as possible, if they think they have symptoms of diverticulitis. The sooner diverticulitis is treated with antibiotics, the lower the risk of complications developing. If people have symptoms of diverticular disease and the condition has previously been diagnosed, they do not usually have to contact their doctor, because the symptoms may be treated at home. If patients have not been diagnosed with the condition, they must contact their doctor, so that they can rule out other conditions with similar symptoms, such as irritable bowel syndrome (IBS).


Diagnosing diverticular disease and diverticulitis 

Diverticular disease may be difficult to diagnose from the symptoms alone, because there are other conditions which cause similar symptoms, such as irritable bowel syndrome (IBS). As a first step, the doctor may recommend blood tests in order to rule out other conditions such as coeliac disease (a condition caused by an abnormal immune response to gluten).


Colonoscopy

In order to confirm a patient has diverticula (small bulges in the side of the colon) the inside of the large intestine (colon) will be looked at. This can be done with a colonoscopy. During a colonoscopy, a thin tube with a camera at the end (a colonoscope) is inserted into the rectum and guided into the colon. Before the procedure begins, patients are given a laxative in order to clear out their bowels.

A colonoscopy is carried out under local anaesthetic (medication which numbs the surrounding area), so it is not painful. People may also be given a sedative to relax them. However, patients may feel a little discomfort during the procedure.
Barium enema X-ray

 Another technique for confirming the presence of diverticula is a barium enema X-ray. Barium is a liquid which shows up on X-rays. It is used to coat the inside surface of organs which do not show up on X-ray, such as the colon. As with a colonoscopy, patients will be given a laxative to clear out their bowels before they have a barium enema X-ray.

During the procedure, a tube is inserted into their rectum. The barium liquid is squirted into the tube and up into the patient's rectum. A series of X-rays are then taken. For a few days after having a barium enema X-ray, the stools will appear white and discoloured due to the barium passing out of the patient's body. It is nothing to worry about.
Diverticulitis

 If patients have had a previous history of diverticular disease, their doctor will usually be able to diagnose diverticulitis from their symptoms and by a physical examination. A blood test can be taken, because a high number of white blood cells and a raised C-reactive protein (CRP) indicate infection or inflammation.

Further tests may be needed if patients have no previous history of diverticular disease. This is to rule out other possible conditions, such as gallstones or a hernia. A barium enema X-ray may be used, as well as a computerised tomography (CT) scan. A CT scan takes a series of X-ray scans, which are then reassembled by a computer, in order to build up a more detailed 3-D image of the inside of the patient's body.

A CT scan can also be used if the symptoms are particularly severe. This is to check whether the infection has spread to other parts of the body or a complication, such as a perforation or an abscess, has occurred.


Treating diverticular disease and diverticulitis 

 Most cases of diverticular disease may be treated at home. The over-the-counter (OTC) painkiller paracetamol is recommended to help relieve the symptoms. Painkillers known as non-steroidal anti-inflammatory drugs (NSAIDs), (e.g. aspirin and ibuprofen/ neurofen), are not recommended, because they may upset the stomach and increase the risk of internal bleeding.

Eating a high-fibre diet may initially help to control the symptoms of diverticular disease. Some people will notice an improvement after a few days, although it may take about a month to fully feel the benefits.

If patients have constipation, they may be given a bulk-forming laxative. These may cause flatulence (wind) and bloating. Patients must drink plenty of fluid, in order to prevent any obstruction in their digestive system.

Heavy or constant rectal bleeding occurs in about one in 20 cases (5%) of diverticular disease. This may happen if the blood vessels in the large intestine (colon) are weakened by the diverticula, making them vulnerable to damage. The bleeding is usually painless, but losing too much blood can be potentially serious and may need a blood transfusion. Signs which patients may be experiencing heavy bleeding (aside from the amount of blood) include:
  • feeling very dizzy
  • mental confusion
  • pale clammy skin
  • shortness of breath
If a patient suspects that they (or someone in their care) is experiencing heavy bleeding, then they need to seek immediate medical advice and they must either contact their doctor immediately, or visit their nearest Accident and Emergency Department. 
Diverticulitis

 Treatment at home

 Mild diverticulitis may often be treated at home. The doctor will usually prescribe antibiotics for the infection and patients must take paracetamol for their pain. It is important that they finish the complete course of antibiotics, even if they are feeling better. Some types of antibiotics whch are used to treat diverticulitis may cause side effects in some people, including vomitting and diarrhoea.
The doctor may recommend that patients stick to a fluid-only diet for a few days until their symptoms improve. This is because trying to digest solid foods may make the patient's symptoms worse. Patients can gradually introduce solid foods over a two or three day period.
Treatment at hospital

If patients have more severe diverticulitis, they may need to go to hospital. Hospital treatment is usually recommended if:
  • the pain cannot be controlled using paracetamol
  • they are unable to drink enough fluids to keep themselves hydrated
  • they are unable to take antibiotics by mouth 
  • their general state of health is poor
  • they have a weakened immune system
  • their doctor suspects complications
  • their symptoms fail to improve after two days  treatment at home
If patients are admitted to hospital for treatment, they are likely to receive injections of antibiotics and to be kept hydrated and nourished using an intravenous drip (a tube directly connected to their vein). Most people start to improve within two to three days.
Surgery

 In the past, surgery was recommended as a preventative measure for people who had two episodes of diverticulitis as a precuation to prevent complications. This is no longer the case, as studies have found that in most cases risks of serious complications from surgery (estimated to be around one in a 100 - 1%) usually outweigh the benefits. However, there are some exceptions to this, including:
  • if patient has a history of serious complications arising from diverticulitis
  • if patient has symptoms of diverticular disease from a young age (it is thought the longer people live with diverticular disease, the greater their chances of having a serious complication)
  • if patient has a weakened immune system or is more vulnerable to infections.

If surgery is being considered, patient must discuss both benefits and risks carefully with the doctor in charge of their care.
Colectomy

 Surgery for diverticulitis involves removing the affected section of the large intestine (colon). This is known as a colectomy. There are two ways this operation can be performed:
  • an open colectomy - where the surgeon makes a large incision (cut) in the abdomen and removes a section of the large intestine,
  • laparoscopic colectomy - a type of "keyhole surgery", where the surgeon makes a number of small incisions in the abdomen, and uses special instruments guided by a camera to remove a section of the large bowel.

 Open colectomies and laparoscopic colectomies are thought equally effective in treating diverticulitis, and have a similar risk of complications. Laparoscopic colectomies have the advantage of having a faster recovery time, and cause less post-operative pain. Laparoscopic colectomies are a relatively new technique, and may only be available at specialist surgical centres. There may also be a longer waiting time for this type of surgery.
Stoma surgery

 In some cases, the surgeon may decide the large intestine needs to heal before it can be reattached, or that too much of the large intestine has been removed to make reattachment possible. In such cases, stoma surgery provides a way of removing waste materials from the body without using all of the large intestine.

Stoma surgery involves the surgeon making a small hole in the abdomen (known as a stoma). There are two ways this procedure can be carried out. These include:
  • An ileostomy - where a stoma is made in the right-hand side of the abdomen (stomach). The small intestine is separated from the large intestine, and connected to the stoma, and the rest of the large intestine is sealed. Patients will need to wear a pouch connected to the stoma, in order to collect waste material.
  • A colostomy - where a stoma is made in the lower abdomen, and a section of the large intestine is removed and connected to the stoma. As with an ileostomy, patients will need to wear a pouch to collect waste material.
In most cases the stoma will be temporary, and it can be removed once the large intestine has recovered from the surgery. This will usually take at least nine weeks. If a large section of the large intestine is affected by diverticulitis and needs to be removed, patients may need a permanent ileostomy or colostomy.
Results of surgery

 In general terms, surgery is usually successful, although it does not achieve a complete cure in all cases. Following surgery, an estimated one in 12 people will have a recurrence of symptoms of diverticular disease and diverticulitis. 


Preventing diverticular disease and diverticulitis 

 Eating a high-fibre diet may help prevent diverticular disease, and should improve the patient's symptoms. Patients' diets must be balanced, and they should include at least five daily portions of fruit and vegetables, plus whole grains. Adults must aim to eat between 18g (0.6oz) to 30g (1.05oz) of fibre a day, depending on their height and weight. The doctor can provide a more specific target, based on a patient's individual height and weight.

It is recommended that patients gradually increase their fibre intake over the course of a few weeks. This will help prevent side effects associated with a high-fibre diet, such as bloating and flatulence (wind). Some specialists may suggest not eating nuts, corn and seeds due to the possibility that they could block the diverticular openings and cause diverticulitis. However, there is limited evidence to support this. Also drinking plenty of fluids will help prevent side effects.
Sources of fibre

 Good sources of fibre include
  • fruit
  • vegetables
  • nuts
  • breakfast cereals
  • starchy foods – such as bread, rice and pasta.

Once patients have reached their fibre target, they must stick to it for the rest of their life if possible.
Fresh fruit

 Good sources of fibre in fresh fruit (plus the amount of fibre which is found in typical portions) include:
  • avocado pear – a medium-sized avocado pear contains 4.9g of fibre
  • pear (with skin) – a medium-sized pear contains 3.7g of fibre
  • orange – a medium-sized orange contains 2.7g of fibre
  • apple (with skin) – a medium-sized apple contains 2g of fibre
  • raspberries – two handfuls of raspberries (80g) contains 2g of fibre
  • banana – a medium-sized banana contains 1.7g of fibre
  • tomato juice – one small glass of tomato jucie (200ml) contains 1.2g of fibre.

Dried fruit

 Good sources of fibre in dried fruit (plus the amount of fibre found in typical portions) include:
  • apricots – three whole apricots contain 5g of fibre
  • prunes – three whole prunes contain 4.6g of fibre.

Vegetables

 Good sources of fibre in vegetables (plus the amount of fibre found in typical portions) include:
  • baked beans (in tomato sauce) – a half can of baked beans (200g) contains 7.4g of fibre
  • red kidney beans (boiled) – three tablespoons of red kidney beans contain 5.4g of fibre
  • peas (boiled) – three heaped tablespoons of peas contains 3.6g of fibre
  • French beans (boiled) – four heaped tablespoons of French beans contains 3.3g of fibre
  • Brussel sprouts (boiled) – eight Brussel sprouts contains 2.5g of fibre 
  • potatoes (old, boiled) – one medium-sized potato contains 2.4g of fibre
  • Spring greens (boiled) – four heaped tablespoons of Spring greens contains 2.1g of fibre
  • carrots (boiled, sliced) – three heaped tablespoons of carrots contains 2g of fibre.

Nuts

Good sources of fibre in nuts (plus the amount of fibre found in typical portions) include:
  • almonds – 20 almonds contain 2.4g of fibre
  • peanuts (plain) – a tablespoon of peanuts contains 1.6g of fibre
  • mixed nuts – a tablespoon of mixed nuts contains 1.5g of fibre
  • Brazil nuts – 10 Brazil nuts contain 1.4g of fibre.

Breakfast cereals

 Good sources of fibre in breakfast cereals (plus the amount of fibre found in typical portions) include:
  • All-Bran – a medium-sized bowl of All-Bran contains 9.8g of fibre
  • Shredded Wheat – two pieces of Shredded wheat contain 4.3g of fibre
  • Bran Flakes – one medium-sized bowl of Bran flakes contains 3.9g of fibre
  • Weetabix – two Weetabix contain 3.6g of fibre
  • muesli (no added sugar) – one medium-sized bowl of muesli contains 3.4g of fibre
  • porridge (milk or water) – one medium-sized bowl of porridge contains 2.3g of fibre.

Starchy foods

 Good sources of fibre in starchy food (plus the amount found in typical portions) include:
  • crispbread – four crispbreads contain 4.2g of fibre
  • pitta bread (wholemeal) – one piece (75g) contains 3.9g of fibre
  • pasta (plain, fresh cooked) – one medium portion of pasta (200g) contains 3.8g of fibre
  • wholemeal bread – two slices of wholemeal bread contain 3.5g of fibre
  • Naan bread – one piece of naan bread contains 3.2g of fibre
  • brown bread – two slices of brown bread contain 2.5g of fibre
  • brown rice (boiled) – one medium portion of brown rice (200g) contains 1.6g of fibre.

Fibre supplements – usually in the form of sachets of powder people mix with water – are also available from pharmacists and health food shops. A tablespoon of fibre supplement contains around 2.5g of fibre.


Complications of diverticular disease and diverticulitis 

 Complications of diverticulitis affect one in five people (20%) with the condition. Those who are most at risk are younger people (under 50 years of age). Some complications associated with diverticulitis include:
Abscess

 The most common complication of diverticulitis is an abscess inside the large intestine (colon). An abscess is a pus-filled cavity or lump in the tissue. Abscesses are usually treated with a technique known as percutaneous abscess drainage (PAD). A radiologist (a specialist in the use of imaging equipment, such as computerised tomography (CT) scans) uses an ultrasound or CT scanner to locate the size and the site of the abscess.

A fine needle connected to a small tube is passed through the skin of the abdomen (tummy) and into the abscess. The tube is then used to drain the pus from the abscess. A PAD is performed under a local anaesthetic, so it is not particularly painful.

Depending on the size of the abscess, the procedure may need repeating several times before all the pus has been drained. If the abscess is very small – usually less than 4cm (1.5in) – it may be possible to treat it using antibiotics.
Fistula

 A fistula is another common complication of diverticulitis. Fistulas are abnormal tunnels which connect two parts of the body together, such as the intestine and the abdominal wall or bladder. If infected tissues come into contact with each other they can stick together. After the tissues have healed, a fistula may form. Fistulas can be potentially serious, as they can allow bacteria in the large intestine to travel to other parts of the body, triggering infections, such as an infection of the bladder (cystitis). Fistulas are usually treated with surgery to remove a small section of the colon which contains the fistula.
Peritonitis

 In rare cases, an infected diverticula (pouch in the colon) can split, spreading the infection into the lining of the abdomen. An infection of the lining of the abdomen is known as peritonitis. Peritonitis may be life-threatening, and requires immediate treatment with antibiotics. Surgery may also be required to repair any damage and drain any pus which has built up.
Intestinal obstruction

 If the infection has badly scarred the large intestine, it may become partially or totally blocked. A totally blocked large intestine is a medical emergency because the tissue of the large intestine will start to decay and eventually split, leading to peritonitis. A partially blocked large intestine is not as urgent, but treatment is still needed. If left untreated, it will affect the patient's ability to digest food, and it will cause patients considerable pain. In some cases, the blocked part may be removed during surgery. However, if the scarring and blockage is more extensive, a temporary or permanent colostomy may be required.

 Source: NHS Choices.