All about Crohn's and Colitis

Last reviewed: February 2024

Next review date: February 2027

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This information is for people who are new to Crohn’s or Colitis. It covers the basics you need to know about the conditions including:

What Crohn’s and Colitis are
The different types of Crohn’s and Colitis
Symptoms that you may experience
What causes Crohn’s and Colitis
Some of the tests that you might have
Some of the treatments that you might be offered
The role of food and diet in managing your Crohn’s or Colitis

This information is available to download in English, Bengali, Gujarati, Polish, Punjabi, Urdu and Welsh.

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Key facts
Crohn’s Disease and Ulcerative Colitis are Inflammatory Bowel Diseases (IBDs). They can cause painful sores (ulcers) and inflammation in your gut.

In Crohn’s Disease the inflammation can be anywhere in the gut, from your mouth to your bottom.

In Ulcerative Colitis the inflammation and ulcers are only in the large bowel.

Microscopic Colitis is another type of colitis. In Microscopic Colitis there is inflammation of the large bowel. But Microscopic Colitis does not cause ulcers.

There will be times when your Crohn’s or Colitis makes you feel unwell. We call these flare-ups. And there will be times when your Crohn’s or Colitis is being controlled well. We call this remission.

There are many different treatments available to help you live well with Crohn’s or Colitis. These include medicines, surgery or both. Together with your IBD team, you can decide what treatment is right for you.

Inflammatory Bowel Disease (IBD) is not the same as Irritable Bowel Syndrome (IBS). IBS can cause tummy pain, bloating, diarrhoea and constipation. But unlike IBD, there is no inflammation, or blood in the poo.
Crohn's and Colitis

Crohn’s Disease and Ulcerative Colitis are Inflammatory Bowel Diseases (IBDs). They can cause painful sores (ulcers) and inflammation (swelling) in your gut.

Crohn’s and Colitis are lifelong conditions, which means you will always have the condition. But that does not mean you will always feel unwell. Treatment like medicines and surgery can help you feel a lot better.

There is another type of colitis called Microscopic Colitis. Unlike Ulcerative Colitis, Microscopic Colitis does not cause ulcers, and there is no blood in the poo.

It’s something you’ll have to learn to adapt to – and you will. Don’t let your mind run riot, and know that things will get better if you let them. Everyone goes through their own stuff in life; if you embrace it, everything becomes a lot easier.

Moeed
Living with Crohn's
The digestive system

The gut

To understand Crohn’s and Colitis, it can help to understand how the gut works.

The gut is the part of your body that takes food and nutrients in and carries poo out. The gut starts at your mouth, when you eat, and ends at your bottom (anus), where poo passes out of your body.

The gut is also called the digestive system, because it digests (breaks down) food.

The bowel is an important part of the gut. It is a long tube, coiled up inside you, made up of your small bowel, colon, and rectum. The colon and rectum make up the large bowel. At the end of your rectum is your anus, where poo passes out of your body.

The walls of your bowel have layers. The layers take in nutrients from food and help get rid of waste.
Types of Crohn's and Colitis

Crohn’s Disease

Crohn’s Disease is inflammation anywhere in the gut, from your mouth to your bottom. Although Crohn’s Disease is called an Inflammatory Bowel Disease, any part of the gut can be affected, not just your bowel. All layers of the gut can be inflamed.

‘Crohn’s Colitis’ is a type of Crohn’s Disease, where only the colon is inflamed. This is because ‘colitis’ means inflammation of the colon. It does not mean you have both Crohn’s Disease and Ulcerative Colitis.

Ulcerative Colitis

Ulcerative Colitis is inflammation and ulcers in the large bowel. It can be anywhere in your colon and your rectum. Only the inner lining of the gut is inflamed.

If only your rectum is inflamed, it’s called proctitis.

Microscopic Colitis

Microscopic Colitis is inflammation of the large bowel. Unlike Ulcerative Colitis, Microscopic Colitis does not cause ulcers. There is frequent watery diarrhoea, but there is no blood in the poo. Doctors must use a microscope to see the inflammation.

Uncertain diagnosis (IBDU)

If your doctor says you have Indeterminate Colitis or IBDU (Inflammatory Bowel Disease Unclassified) it’s not certain whether you have Crohn’s or Colitis.
Who has Crohn's and Colitis?

In the UK, 1 in 123 people have Crohn’s or Colitis. That’s more than 500,000 people.

Crohn’s Disease and Ulcerative Colitis can start at any age, but they usually start before you are 30.

Microscopic Colitis is more common in women and usually starts after 50.
Feeling unwell
Everyone is different. Some people with Crohn’s or Colitis feel well most of the time. Others may feel unwell more often or for longer periods of time.

Not everyone feels the same, and how you feel can change over time.

Crohn’s and Colitis can cause:

Cramping pains

Frequent and urgent diarrhoea, sometimes with blood and thick liquid (mucus)

Swollen joints

Mouth ulcers

Tiredness

Lack of iron (anaemia)

Losing weight and not wanting to eat

Inflamed eyes

If you have Crohn’s, you may also get cracks (fissures) in the skin around your bottom. Sometimes your gut can become narrow (strictures). Your IBD team are there to help. Talk to them if you notice anything unusual for you.

Flare-ups

Times when you feel unwell are called flare-ups.

Taking your medicines regularly, even when you feel better, can help stop flare-ups happening.

Your doctor (gastroenterologist) and the rest of your IBD team are there to support you. Ask your hospital if they have an IBD nurse you can speak to if you need help in between appointments. Or search our map to find your local specialist service.

Remission

Remission is when your Crohn’s or Colitis is being controlled well. You should continue to take your medicines even when you feel better.

Many people still feel tired even when their Crohn’s or Colitis is under control, so it’s important to rest when you need to.

If you still feel unwell in your gut, even when your doctor says you’re in remission, you may also have a condition called irritable bowel syndrome (IBS). Inflammatory Bowel Disease (IBD) and IBS are different, but you can have both at the same time. IBS is very common, and can cause tummy pain, bloating, diarrhoea, and constipation. But unlike Crohn’s and Colitis, there is no inflammation, or blood in the poo.

If you have IBS as well as Crohn’s or Colitis, you may need treatment for both.
Causes of Crohn's and Colitis

Crohn’s and Colitis happen when the body’s immune system goes wrong.

Usually, the immune system protects the body. In Crohn’s and Colitis, the immune system starts attacking the body.

We do not know why the immune system attacks the body. It is probably caused by a mix of genes, bacteria in the gut, and the environment (like germs, diet, smoking, and stress).
Tests

To find out if you have Crohn’s or Colitis, you probably had lots of tests. The same tests help your doctors check (monitor) your health and find the best treatment for you.

Tests for Crohn’s and Colitis include:

Blood tests

Blood tests check for inflammation, signs of infection, and low iron levels. They can also show if you are getting enough nutrients and vitamins.

Poo tests

Poo tests check for infections and inflammation.

Endoscopy

Your doctor looks at your gut with a tiny camera on a long, thin tube (endoscope). The tube goes through your mouth (gastroscopy) or up your bottom (sigmoidoscopy or colonoscopy).

The doctor can take tiny pieces of your gut (biopsy) to check for inflammation.

Ultrasound, CT and MRI scans

Scans help doctors see how much inflammation you have, and where it is in your body.

See our information on Tests and investigations for further details
Treating Crohn's Disease and Ulcerative Colitis
There are many different treatments available to help you live well with Crohn’s or Colitis. Together with your IBD team, you can decide what treatment is right for you.

Medicines

To start, you will probably have medicines to reduce the gut inflammation. You might be given a medicine called steroids. Steroids work quickly, but you can only take them for a short time. If you have Colitis you might be given a medicine called a 5-ASA (such as mesalazine). 5-ASAs do not work so well for Crohn’s.

If you still feel unwell, you can take medicine to control your immune system. This might be a medicine called a biologic or another targeted treatment. These medicines stop your immune system attacking your gut.

You can have your medicine in different ways:

Tablet

Injection

Drip into your arm (infusion)

Suppository or enema, which go directly into your bottom

See our information on Treatments for Crohn’s and Colitis for more information.

Liquid diet

Sometimes Crohn’s flare-ups can be treated with a liquid diet. This is called enteral or parenteral nutrition.

Surgery

Medicines are important for managing Crohn’s and Colitis, but surgery can also be an effective treatment. Some people may have both medicines and surgery. Whether your IBD team suggests surgery as an option and what type of surgery you have will depend on:

Whether you have Crohn’s or Colitis, and the part of your gut affected

How bad your symptoms are

How well medicines are working and if you have any side effects

Any problems you might have

Surgery can remove the part of the bowel that’s making you feel unwell. If a lot of bowel is removed, you may need a stoma bag. This is when your bowel is brought outside your tummy, and your poo goes straight into the stoma bag.

Having bowel surgery can be daunting, but many people find having a stoma is easier than feeling unwell with Crohn’s or Colitis.

We have more information on Surgery for Crohn's Disease and Surgery for Ulcerative Colitis.
Treating Microscopic Colitis

Some medicines can trigger Microscopic Colitis. Common medicines that can trigger Microscopic Colitis include acid-lowering medicines, such as omeprazole or lansoprazole, and NSAID painkillers, such as ibuprofen. So if you stop taking these medicines, you may feel better.

Making changes to your diet and lifestyle may help. Common triggers are smoking, caffeine, and alcohol.

People with Microscopic Colitis are also more likely to have coeliac disease. Ask your doctor to test if you have this. You should include gluten in your diet when you have the blood test. This is because avoiding it could lead to a wrong result. If you do have coeliac disease, avoiding foods with gluten will help you feel better.

Medicines

Your doctor might give you tablets to stop your diarrhoea, or a steroid called budesonide.

If you have very severe Microscopic Colitis that does not respond to steroids, your doctor might offer you a medicine called an anti-TNF medicine.

Be self-aware and find out everything you can. It’s easier if you can simply see it as part of you – and deal with it in a positive way.

Helen
Living with Microscopic Colitis
Diet

There’s no single diet that helps Crohn’s or Colitis. Keeping a food diary can help you find what works for you. Spicy and high fibre foods (like vegetables, nuts and wholegrains) make a lot of people feel worse when they’re in a flare-up. But everyone is different.

The right diet also depends on how your Crohn’s or Colitis affects you. For example, if you have a narrowing in the gut (stricture) that makes it harder to digest food.

It’s important to eat a balanced diet. Talk to your doctor or a qualified dietitian before making any big changes.

See our information on Food for further details.
About this information
We follow strict processes to make sure our information is based on up-to-date evidence and easy to understand.

Please email us at evidence@crohnsandcolitis.org.uk if:

You have any comments or suggestions for improvements

You would like more information about the sources of evidence we use

You would like details of any conflicts of interest

You can also write to us at Crohn’s & Colitis UK, 1 Bishop Square, Hatfield, AL10 9NE, or contact us through our Helpline: 0300 222 5700

All about Crohn's and Colitis

Help us improve our information

The gut

Crohn’s Disease

Ulcerative Colitis

Microscopic Colitis

Uncertain diagnosis (IBDU)

Blood tests

Poo tests

Endoscopy

Ultrasound, CT and MRI scans

Medicines

Liquid diet

Surgery

Medicines

About
Crohn's and Colitis

Support
for you

Useful links

All about Crohn's and Colitis

This information is also available to download inGujarati, Bengali, Punjabi, Urdu, Welsh and Polish

Help us improve our information

The gut

Crohn’s Disease

Ulcerative Colitis

Microscopic Colitis

Uncertain diagnosis (IBDU)

Blood tests

Poo tests

Endoscopy

Ultrasound, CT and MRI scans

Medicines

Liquid diet

Surgery

Medicines

Other informationyou might find helpful

AboutCrohn's and Colitis

Supportfor you

Useful links

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HelplineService

Stay inthe loop

This information is also available to download in
Gujarati, Bengali, Punjabi, Urdu, Welsh and Polish

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