Crohn’s disease

Posted in Disease Information

Introduction

Crohn’s disease is a long-term condition that causes inflammation of the lining of the digestive system.

Inflammation can affect any part of the digestive system, from the mouth to the back passage, but most commonly occurs in the last section of the small intestine (ileum) or the large intestine (colon).

Common symptoms of Crohn’s disease include:

• Diarrhoea
• Abdominal pain
• Fatigue (extreme tiredness)
• Weight loss

Over time, inflammation can damage sections of the digestive system, resulting in additional complications, such as narrowing of the colon.

People with Crohn’s disease sometimes go for long periods (weeks or months) without symptoms, or with very mild symptoms. This is known as remission. Remission can be followed by periods where a person’s symptoms flare up and become particularly troublesome.

What causes Crohn’s disease?

The exact cause of Crohn’s disease is unknown. However, research suggests that a combination of factors may be responsible. These include:

• genetics – genes that you inherit from your parents may increase your risk of developing Crohn’s disease
• the immune system – it seems that the immune system (the body’s natural defence against infection and illness) is responsible for the inflammation in the digestive system
• previous infection – a previous infection may trigger an abnormal response from the immune system
• environmental factors – Crohn’s disease is most common in westernised countries,  and least common in poorer parts of the world, such as Africa, which suggests the environment has a part to play
• smoking – smokers with Crohn’s disease usually have more severe symptoms than non-smokers

A colonoscopy is the most common test used to diagnose Crohn’s disease. There are several other tests that may be used to help rule out other conditions that might be causing your symptoms.

Treating Crohn’s disease

There is currently no cure for Crohn’s disease so the aim of treatment is to control the symptoms. Several different types of medication can be used to reduce your symptoms. In many cases, surgery will also be needed.

Around 60-75% of people with Crohn’s disease need surgery to relieve their symptoms, repair damage to their digestive system and treat related complications.

If your symptoms are severe, your doctor may recommend an elemental (liquid only) diet on a temporary basis.

Although there is currently no clinical evidence, some people find that certain foods, such as dairy products, fatty foods and spicy foods, can worsen symptoms in some people. Therefore, eliminating them from your diet may help.

Complications of Crohn’s disease

The two most common complications associated with Crohn’s disease are bowel obstruction and fistula.

Bowel obstruction

Severe inflammation can cause sections of the bowel to narrow and harden, causing the contents of the bowel to become stuck.

Fistula

A fistula is a channel that develops between the end of the bowel (anal canal) and the skin near the anus. Surgery is usually required to treat a fistula.

If you think that your bowel is obstructed, contact Dr. B C Shah immediately.

Who is affected by Crohn’s disease?

Crohn’s disease is a rare condition. Most cases of Crohn’s disease first develop in people who are between 16 and 30 years of age. A large number of cases also develop in people between the ages of 60 and 80. However, Crohn’s disease can affect people of all ages, including children. It affects slightly more women than men.

Crohn’s disease is more common in white people than in black or Asian people. It is most prevalent among Jewish people of European descent.

Symptoms of Crohn’s disease

The symptoms of Crohn’s vary depending on which part of the intestine is inflamed.

There may be long periods that last for weeks or months where you have very mild or no symptoms, followed by periods where the symptoms are particularly troublesome. These are known as flare-ups.

Common symptoms of Crohn’s disease include:

• Recurring diarrhoea
• Abdominal pain and cramping (the pain is usually worse after eating)
• Extreme tiredness (fatigue)
• Weight loss

You may find that you experience all or only one of the above.

Weight loss can be caused by a combination of factors. For example, inflammation can interfere with your ability to digest food, and the symptoms of pain and diarrhoea can reduce your appetite.

Less common symptoms of Crohn’s disease include:

• High temperature (fever) of 38°C (100°F) or above
• Feeling sick (nausea)
• Being sick (vomiting)
• Joint pain and swelling (arthritis)
• Inflammation and irritation of the eyes (uveitis)
• Skin rashes
• Blood and mucus in your faeces (stools)

When to seek medical advice

You should contact Dr. B C Shah if you have:

• Persistent diarrhoea that does not respond to over-the-counter (OTC) medication
• Persistent abdominal pain
• Unexplained weight loss
• Blood in your faeces (stools)

Causes of Crohn’s disease

The exact cause of Crohn’s disease is unknown. Most researchers think that it is caused by a combination of factors.

The main contributory factors are thought to be:

• Genetics
• The immune system
• Previous infection
• Environmental factors
• Smoking

These are discussed in more detail below.

Genetics

There is evidence to suggest that genetics plays a role in the development of Crohn’s disease.

Researchers have identified 32 different specific genetic mutations (alterations) that are more common in people with Crohn’s disease than in the general population.

There is also evidence that Crohn’s disease can run in families. About 3 in 20 people with the condition have a close relative (mother, father, sister or brother) who also has Crohn’s disease. If you have an identical twin with Crohn’s disease, you have a 70% chance of also developing it.

The fact that Crohn’s disease is more common in some ethnic groups than in others also suggests that genetics plays an important role.

The immune system

The immune system provides protection against harmful bacteria that could potentially find their way into the digestive system.

The digestive system is also home to more than 500 different types of so-called ‘friendly bacteria’ that help to digest food. The immune system has to recognise these bacteria and let them do their job without attacking them.

It seems that, in Crohn’s disease, something disrupts the immune system, which sends a special antibody, known as tumour necrosis factor (TNF), to kill all bacteria, regardless of whether they are friendly or not. It is the TNF antibodies that cause most of the inflammation associated with Crohn’s disease.

Previous infection

In certain genetically susceptible individuals, a previous childhood infection may lead to an abnormal immune response, causing the symptoms of Crohn’s disease.

One possible source of this infection is a bacterium called Mycobacterium avium subspecies paratuberculosis (MAP). MAP is commonly found in cows, sheep and goats.

Research has found that people with Crohn’s disease are seven times more likely to have traces of MAP in their blood compared with the general population.

MAP has been known to survive the pasteurisation process (where milk is treated with heat to kill bacteria), so it is possible that people have become infected with MAP by drinking milk from contaminated animals.

However, the exact role that MAP may play in the development of Crohn’s disease is uncertain.

Environmental factors

There are two unusual aspects of Crohn’s disease that have led many researchers to believe that environmental factors may play a part. These are explained below.

• Crohn’s disease is a ‘disease of the rich’.
• Crohn’s disease became much more widespread from the 1950s onwards. Before the Second World War the condition was rare.

This suggests that there is something associated with modern, western lifestyles that increases a person’s risk of developing Crohn’s disease.

One theory to explain this is known as the hygiene hypothesis. It suggests that as children grow up in increasingly germ-free environments, their immune system does not fully develop due to a lack of exposure to childhood infections. However, there is little in the way of hard, scientific evidence to support this theory.

An alternative theory is the cold-chain hypothesis, which suggests that the increase in the number of cases of Crohn’s disease might be linked to the increased use of refrigerators after the Second World War.

Psychrotrophic bacteria are bacteria that can survive, and sometimes grow, in cold environments. The cold-chain hypothesis theorises that, as people eat more chilled foods, their exposure to these bacteria increases and it is this that causes the abnormal immune response.

Traces of psychrotrophic bacteria have been found in people with Crohn’s disease, although, as the researchers behind the cold-chain hypothesis admit, this could be pure coincidence.

Smoking

Aside from family history and ethnic background, smoking is the most important risk factor for Crohn’s disease. Smokers are twice as likely to develop Crohn’s disease compared with non-smokers.

Furthermore, people with Crohn’s disease who smoke usually experience more severe symptoms compared with those with the condition who do not smoke.

Diagnosing Crohn’s disease

The two most common complications associated with Crohn’s disease are:

• Bowel obstruction – severe inflammation that causes sections of your bowel to narrow and harden, causing your bowel contents to become stuck in your bowel
• Fistula – a fistula is a channel that develops between the end of the bowel (anal canal) and the skin near the anus

These are discussed in more detail below.

Bowel obstruction

If your bowel becomes obstructed, you will either not be able to pass any stools, or you will only be able to pass watery stools.

Other symptoms of bowel obstruction include:

• Abdominal pain and cramping
• Being sick (vomiting)
• Bloating
• An uncomfortable feeling of fullness in your abdomen

A bowel obstruction requires immediate medical treatment. Left untreated, there is a risk that the bowel could split (rupture). This can lead to internal bleeding and widespread infection.

If you suspect that your bowel is obstructed, contact Dr. B C Shah as soon as possible.

If a bowel obstruction is suspected, it is likely that you will be admitted to hospital so that your health can be carefully monitored. In some cases, it may be possible to clear the obstruction by switching you to a liquid-only diet and using medication to reduce inflammation. However, if this does not work, surgery will be required to unblock the bowel.

Temporary colostomy or ileostomy

You may require a temporary colostomy while your bowel heals. A colostomy is an operation to divert a section of your colon and attach it to an opening in your abdominal wall. The opening is known as a stoma. A pouch is attached to the stoma to collect your stools. Once your bowel has healed, the colon can be reattached and the stoma sealed.

An ileostomy is where a section of your small bowel is diverted and attached to an opening in your abdominal wall.

If you have repeated episodes of bowel obstruction, a permanent colostomy may be recommended.

Fistulas

If your digestive system becomes scarred due to excessive inflammation, ulcers can develop.

Over time the ulcers develop into tunnels, or passageways, that run from one part of your digestive system to another or, in some cases, to the bladder, anus or skin. These passageways are known as fistulas.

Small fistulas do not usually cause symptoms. However, larger fistulas can become infected and cause symptoms such as:

• a constant, throbbing pain
• a high temperature (fever) of 38°C (100°F) or above
• blood or pus in your faeces (stools)

If a fistula develops on your skin (usually on, or near, the anus) it may release a foul-smelling discharge.

Surgery is usually required to treat a fistula. During the operation,Dr. B C Shah will cut open the fistula while you are under general anaesthetic. They will flush out the contents of the fistula and it should then heal into a flat scar.

Several other tests may be used to rule out other possible causes of your symptoms, such as ulcerative colitis (a condition that causes inflammation of the colon).

Initial assessment

During your initial assessment, it is likely that Dr. B C Shah will ask you about the pattern of your symptoms and check whether there may be any contributing causes, such as:

• Diet
• Recent travel – for example, you may have developed travellers’ diarrhoea while travelling abroad
• Whether you are taking any medication, including any over-the-counter (OTC) medicines
• Whether you have a family history of Crohn’s disease

Dr. B C Shah may also carry out a series of standard tests to assess your general state of health. For example, they may:

• Check your pulse
• Check your blood pressure
• Measure your weight and height
• Measure your temperature
• Examine your abdomen

Blood tests

The next stage of the diagnosis is to refer you for a series of blood tests. These can be used to assess:

• The levels of inflammation in your body
• Whether you have an infection
• Whether you have anaemia (low levels of red blood cells), which could suggest you are malnourished

Stool sample

You may be asked to provide a stool sample for testing. The stool sample can be checked for blood and mucus. It can also be used to determine whether your symptoms are being caused by a parasitic infection, such as roundworm.

Colonoscopy

A colonoscopy is a test used to examine the inside of your colon. It involves inserting a long flexible tube, known as an endoscope, into your back passage (rectum) and up into your colon.

The endoscope has a light and a camera on the end. The camera can be used to send images to a television screen. These will show the level and extent of inflammation inside your colon.

The endoscope can also be fitted with surgical tools that can be used to take a number of small tissue samples from different sections of your digestive system. This is known as a biopsy. The procedure may feel uncomfortable but it is not painful.

These tissue samples will be examined under a microscope for the distinctive cell changes known to occur in cases of Crohn’s disease.

Small bowel enema (SBE)

A small bowel enema (SBE) is a test to examine the inside of the small intestine, usually at the point where it meets the colon. This area cannot be seen using a colonoscopy.

During an SBE, a local anaesthetic spray is used to numb the inside of your nose and throat. A tube is passed down your nose and into your throat, before being threaded into your small intestines. This can feel unpleasant at first, but most people find that they get used to the sensation after a few minutes.

A liquid called barium is passed down the tube. The barium coats the lining of your small intestines so that they show up clearly on X-rays. A series of X-ray images will then be taken. The images can often highlight the areas of narrowing and inflammation that are caused by Crohn’s disease.

After the test, you will be advised to drink plenty of fluid to help wash the barium out of your body. You may notice that your stools are whiter than usual for the first few days after having an SBE. This is perfectly normal and it is nothing to worry about.

Further testing

Further testing is usually only required if the results of the above tests are uncertain, or if it is thought that you may have developed complications, such as a blockage in your colon or an abscess (a pus-filled cavity).

Tests that you may have include a:

• Computerised tomography (CT) scan – where several X-rays are taken and assembled by computer to create a more detailed image
• Magnetic resonance imaging (MRI) scan – where a magnetic field and radio waves are used to produce detailed images of the inside of your body
• Wireless capsule endoscopy

A wireless capsule endoscopy is a new type of test that involves swallowing a small capsule (about the size of a headache tablet). The capsule works its way down to your small intestines where it transmits images to a computer.

A few days after the test, the capsule passes out of your body in a stool. The capsule is disposable so you do not have to worry about retrieving it from your stools.

Treating Crohn’s disease

There is currently no cure for Crohn’s disease. However, medication can improve your symptoms and in many cases surgery can also help.

Your treatment plan

If you are diagnosed with Crohn’s disease, Dr. B C Shah will draw up a treatment plan for you. There are three goals in treating the condition. These are:

• To treat the active disease to relieve your symptoms
• To prevent your symptoms returning using maintenance therapy
• To treat any returning symptoms with relapse therapy

Corticosteroids

Corticosteroids, or steroid medications, are a type of hormone medication. Hormones are groups of powerful chemicals that have a wide range of effects on the body, such as helping to reduce inflammation.

Corticosteroids are usually only used to treat active Crohn’s disease because their long-term use causes side effects.

Budesonide and prednisolone are two steroid medications used to treat Crohn’s disease.

Budesonide

Budesonide is usually the first steroid medication prescribed. If you take budesonide on a short-term basis (less than 12 weeks), you may experience the following side effects:

• Acne
• Swelling of the face
• Swelling of the hands, arms, feet and legs due to a build-up of fluid (oedema)
• Mood changes, such as feeling irritable or anxious
• Difficulty sleeping (insomnia)
• Indigestion

If you take budesonide for more than 12 weeks, you may experience:

• Thinning of the bones (osteoporosis)
• Increased vulnerability to infection
• Cataracts (a type of eye condition)
• Muscle cramps and stiffness

If you need to take budesonide for more than 12 weeks, you may be given vitamin D and calcium supplements to help strengthen the bones and protect against osteoporosis.

Due to your increased vulnerability to infections, you should avoid close contact with people who are known to have infections, particularly those with chickenpox, measles and shingles.

You should not suddenly stop taking budesonide. When you no longer need to take budesonide, your dose will be gradually reduced over time.

Prednisolone

Prednisolone is used if budesonide hasn’t helped or your symptoms are more severe.

Prednisolone has the same type of short-term and long-term side effects as budesonide. It has also been known to cause mental health problems in an estimated 5% of people. These include:

• Feeling depressed and thinking about suicide
• Feeling very excited and happy
• Experiencing sudden and severe mood changes (happy one minute, very depressed the next)
• Feeling anxious
• Problems thinking clearly and feeling particularly confused
• Memory loss
• Hallucinations (seeing and hearing things that are not real)

If you experience any of these symptoms, you should contact Dr. B C Shah because your dose may need to be adjusted.

As with budesonide, you should avoid close contact with people who are known to have infections, particularly those with chickenpox, measles and shingles.

You should not suddenly stop taking prednisolone. Speak to Dr. B C Shah and your dose will be gradually reduced over time.

Aminosalicylates

Sulfasalazine

Sulfasalazine belongs to a group of medicines called aminosalicylates. Aminosalicylates are known to reduce inflammation inside the colon. Sulfasalazine may be used as an alternative to steroid medications to treat mild cases of Crohn’s disease.

Depending on exactly where the inflammation is, you may be given sulfasalazine as a tablet or as a suppository (a capsule that you insert into your anus).

Common side effects of sulfasalazine include:

• Headaches
• Nausea
• Abdominal pain
• Diarrhoea

You should tell Dr. B C Shah if you have side effects that become particularly troublesome because your dose may need to be adjusted.

Immunosuppressants

Immunosuppressants are a type of medication used to suppress the immune system to help reduce inflammation on a long-term basis.

Immunosuppressants are used in maintenance therapy and in combination with corticosteroids when symptoms relapse.

Azathioprine and mercaptopurine are two immunosuppressants often used to treat Crohn’s disease.

Azathioprine

Depending on the severity of your symptoms, you may be given azathioprine as a tablet or as an injection.

Common side effects of azathioprine include:

• Increased vulnerability to infection
• Bleeding and bruising more easily

Due to your increased vulnerability to infection, you should avoid people with a known chickenpox or shingles infection.

Less common side effects of azathioprine include:

• Headaches
• Shortness of breath and dizziness when exercising
• Feeling sick (nausea)
• Being sick (vomiting)

Mercaptopurine

Mercaptopurine was originally developed to treat leukaemia (cancer of the blood cells), but it has since proved effective in treating Crohn’s disease.

Common side effects of mercaptopurine include:

• Nausea (feeling sick)
• Vomiting (being sick)

Less common side effects of mercaptopurine include:

• Loss of appetite
• Feeling tired, breathless and weak, which is caused by anaemia (a decrease in the number of red blood cells)

Mercaptopurine can also temporarily affect the quality of a woman’s eggs and a man’s sperm, which could increase the risk of birth defects. It is therefore very important to use effective contraception if you are sexually active and taking mercaptopurine.

Biological therapies

Biological therapies are a new type of medication. They are created using naturally occurring biological substances, such as antibodies and enzymes.

There are currently two biological therapies which are:

• infliximab
• adalimumab

Infliximab

Infliximab is usually only recommended in severe cases of Crohn’s disease that have not responded to other treatments or surgery.

For example, if a person has had surgery to remove a section of bowel, they may not be suitable for more surgery. Alternatively, a person’s overall health may be too poor to withstand the effects of surgery.

Infliximab works by targeting the tumour necrosis factor (TNF) antibodies responsible for most of the inflammation associated with Crohn’s disease.

Infliximab is given through a drip in your arm over the course of two hours. This is known as an infusion.

An initial dose of infliximab is followed by a second dose two weeks later. If there is no response then treatment with infliximab will stop. If there is a response to the infliximab, there will be further treatment 6 weeks after the initial dose, followed by infusions every 8 weeks.

Around 1 in 4 people have an allergic reaction to infliximab and experience symptoms such as:

• Joint and muscle pain
• Itchy skin
• High temperature
• Rash
• Swelling of the hands or lips
• Problems swallowing
• Headaches

These symptoms can range from mild to severe and usually develop in the first two hours after the infusion has finished. However, in a minority of cases, people have experienced a delayed allergic reaction that occurs days or even weeks after having an infusion. If you begin to experience any of the side effects of infliximab, you should seek immediate medical assistance.

Your health will be closely monitored following your first infusion, due to the significant risk of having a severe allergic reaction.

There have been several cases where infliximab has reactivated a previously dormant tuberculosis (TB) infection. Therefore, it may not be suitable for you if you have a previous history of TB. Infliximab is also not recommended for people with a history of heart disease.

Infliximab makes you more vulnerable to infection so you should avoid contact with people who have a known chickenpox or shingles infection.

Adalimumab

Another biological therapy available for people with severe Crohn’s disease is a medication called adalimumab. Adalimumab works in a similar way to infliximab, by targeting TNF antibodies.

Adalimumab is given by injection. Most people will need to have an injection every two weeks. Dr. B C Shah or practice nurse will be able to teach you how to administer the injections yourself at home.

Like infliximab, adalimumab makes you more vulnerable to infection, so if you are taking it you should avoid coming into contact with people with chickenpox or shingles, and you should always report any symptoms of a possible infection to Dr. B C Shah.

Adalimumab can cause reactivation of the hepatitis B virus in people who were previously infected. You should let Dr. B C Shah know if you’ve been previously infected with hepatitis B.

Common side effects of adalimumab include:

• Pain, swelling, redness and itching at the site of the injection
• Headache
• Nausea (feeling sick)
• Vomiting (being sick)
• Skin rash
• Muscle, joint and bone pain
• Respiratory tract infections, such as colds, a runny nose and pneumonia (lung infection)

Surgery

Surgery is often required when the symptoms of Crohn’s disease cannot be controlled using medication alone. An estimated 60-75% of people with Crohn’s disease will need to have surgery at some point. Surgery may also be required to treat complications such as fistulas (abnormal channels that develop between two sections of the digestive system).

Surgery cannot cure Crohn’s disease, but it can ease the symptoms for long periods of time. During surgery, the inflamed section of the digestive system is removed and the remaining part is reattached.

Diet and self-help

Some people with Crohn’s disease find that certain foods make their symptoms worse and decide to try a different a diet. In cases where the symptoms of Crohn’s disease are severe, a liquid diet (elemental diet) may be recommended by Dr. B C Shah.

Self-help for people with Crohn’s disease

There is no evidence to suggest that diet causes or plays a role in Crohn’s disease. However, some people with the condition have found that certain foods seem to aggravate their symptoms. 

Dr. B C Shah may also suggest that you try an elemental (liquid only) diet if your symptoms are severe.

Diet

Types of food and drink that have been associated with worsening symptoms include:

• Milk and dairy products
• Alcohol
• Spicy foods
• Fatty foods
• High-fibre foods

However, there are no definitive dietary recommendations for Crohn’s disease because different people react differently to certain foods. You may find it useful to keep a food diary to make a note of the foods that you eat and to record the effects that they have on your symptoms.

Eating six smaller meals a day, rather than three larger meals, may also help to improve your symptoms.

Some researchers have suggested that an elimination diet may help to control the symptoms of Crohn’s disease. An elimination diet involves permanently removing entire food types, such as grains or sugars, from your diet.

However, an elimination diet is a controversial approach to treating Crohn’s disease and it is not supported by many experts who work in the field. Therefore, you should not attempt an elimination diet without first consulting Dr. B C Shah.

You may also require vitamin and food supplements if you are unable, or unwilling, to eat certain foods. For example, as dairy products are an important source of calcium, you will require calcium supplements if you are no longer able to eat dairy products. Dr. B C Shah will be able to advise you about any supplements that may be appropriate for you.

Elemental diet

Dr. B C Shah may recommend an elemental diet if your symptoms are particularly severe, or if you are showing signs of malnutrition (when your diet does not contain enough nutrients to meet the demands of your body).

An elemental diet is a liquid-only diet where all of your nutritional needs are met by drinking specially prepared liquid meals. It is a useful way of allowing your digestive system to rest while ensuring that you get all the nutrients that you require. In most cases, people only have to stay on an elemental diet on a short- to medium-term basis.

Stop smoking

Smokers are twice as likely to develop Crohn’s disease and have a significantly higher chance of relapse after surgery. People who stop smoking after having surgery for Crohn’s disease reduce their risk of having a relapse by 65% compared with those who continue to smoke.

Complications of Crohn’s disease

The two most common complications associated with Crohn’s disease are:

• Bowel obstruction – severe inflammation that causes sections of your bowel to narrow and harden, causing your bowel contents to become stuck in your bowel
• Fistula – a fistula is a channel that develops between the end of the bowel (anal canal) and the skin near the anus

These are discussed in more detail below.

Bowel obstruction

If your bowel becomes obstructed, you will either not be able to pass any stools, or you will only be able to pass watery stools.

Other symptoms of bowel obstruction include:

• Abdominal pain and cramping
• Being sick (vomiting)
• Bloating
• An uncomfortable feeling of fullness in your abdomen

A bowel obstruction requires immediate medical treatment. Left untreated, there is a risk that the bowel could split (rupture). This can lead to internal bleeding and widespread infection.

If you suspect that your bowel is obstructed, contact Dr. B C Shah as soon as possible.

If a bowel obstruction is suspected, it is likely that you will be admitted to hospital so that your health can be carefully monitored. In some cases, it may be possible to clear the obstruction by switching you to a liquid-only diet and using medication to reduce inflammation. However, if this does not work, surgery will be required to unblock the bowel.

Temporary colostomy or ileostomy

You may require a temporary colostomy while your bowel heals. A colostomy is an operation to divert a section of your colon and attach it to an opening in your abdominal wall. The opening is known as a stoma. A pouch is attached to the stoma to collect your stools. Once your bowel has healed, the colon can be reattached and the stoma sealed.

An ileostomy is where a section of your small bowel is diverted and attached to an opening in your abdominal wall.

If you have repeated episodes of bowel obstruction, a permanent colostomy may be recommended.

Fistulas

If your digestive system becomes scarred due to excessive inflammation, ulcers can develop.

Over time the ulcers develop into tunnels, or passageways, that run from one part of your digestive system to another or, in some cases, to the bladder, anus or skin. These passageways are known as fistulas.

Small fistulas do not usually cause symptoms. However, larger fistulas can become infected and cause symptoms such as:

• A constant, throbbing pain
• A high temperature (fever) of 38°C (100°F) or above
• Blood or pus in your faeces (stools)

If a fistula develops on your skin (usually on, or near, the anus) it may release a foul-smelling discharge.

Surgery is usually required to treat a fistula. During the operation, Dr. B C Shah will cut open the fistula while you are under general anaesthetic. They will flush out the contents of the fistula and it should then heal into a flat scar.