In the UK, 1 in 123 people have an autoimmune condition called inflammatory bowel disease (IBD). One type of inflammatory bowel disease is known as Crohn’s, which causes areas of inflammation throughout the digestive system. In this article, Dr Marcus Harbord, Consultant Gastroenterologist, discusses treatment options for this condition.
What is Crohn's disease?
Crohn’s disease is one of two types of inflammatory bowel disease (IBD). It causes your digestive system (the gut) to become inflamed and irritated.
The gut begins at your mouth, where food intake occurs, and ends at your bottom (anus), where stool passes out of the body. In Crohn’s disease, inflammation can occur anywhere within the gut; however, it is most often found in the small and large intestines (colon).
Crohn’s is a chronic autoimmune condition – meaning it lasts for your entire life – and symptoms may come and go, varying in severity. When symptoms are present, it is often called a flare-up or relapse. At other times you may have no symptoms at all, which is called remission.
There are different types of Crohn’s disease depending on where your inflammation is located; the most common type is ileocolitis, where inflammation occurs in the lower small intestine and part of the large intestine.
Although it is a lifelong condition, the symptoms of Crohn’s disease can often be successfully controlled through medication, surgery, or a combination of both.
Crohn’s disease and IBD should not be confused with irritable bowel syndrome (IBS), which is another type of bowel condition with different treatment methods.
What causes Crohn's disease?
Crohn’s disease occurs because the immune system decides to attack the digestive system.
Unfortunately, we don’t exactly know why the condition develops in some people and not others – but it’s likely due to a combination of factors, including genetics, bacteria in the gut, and lifestyle (such as smoking, diet, and stress exposure).
Risk factors for Crohn's disease
There are several risk factors that may increase your chance of developing Crohn’s disease.
- Age – Most people develop Crohn’s disease before the age of 30.
- Ethnicity – Crohn's disease most commonly affects white populations, although it can be found in people of any ethnicity.
- Family history – You have an increased risk of developing Crohn’s disease if a first-degree relative (e.g. parent or sibling) has it.
- Smoking – You have an increased risk of developing Crohn’s disease if you smoke. Additionally, if you already have Crohn’s, smoking can make the condition worse.
Crohn’s disease vs ulcerative colitis
Like Crohn’s, ulcerative colitis is a type of IBD. The primary difference between the two conditions is that ulcerative colitis only affects the colon.
While people with Crohn’s disease will usually have healthy parts of intestine alongside the inflamed areas, inflammation is continuous and restricted to parts or all of the colon.
Ulcerative colitis only affects the innermost lining of the colon, whereas Crohn’s disease can occur within all linings of the digestive tract.
Symptoms of Crohn’s disease
The symptoms of Crohn’s disease can fluctuate in intensity, but the most common symptoms are:
- stomach pain or cramps
- diarrhoea
- blood in your stool
- bowel incontinence
- weight loss
These symptoms may appear suddenly or develop gradually.
Symptoms can also occur in other areas of the body. These include:
- mouth ulcers
- fatigue and tiredness
- sore, red eyes
- joint pain
- skin rashes
- fever
Complications of Crohn’s disease
Left untreated, Crohn’s disease may lead to the development of other conditions. These include:
- Osteoporosis – where the bones become weaker. This is because, when you have Crohn’s, the intestines struggle to absorb enough vitamin D.
- Kidney stones – specifically a type of kidney stone called oxalate, which occurs because your small intestine is less able to absorb fat.
- Fistulas – an abnormal tunnel between two internal organs.
- Stricture – when the gut narrows due to scar tissue or severe inflammation. In rare cases, this can cause an obstruction and require surgery to resolve.
- Perforations – when a hole develops within the bowel wall, due to severe inflammation or stricture, and the bowel contents leak through. This is a medical emergency that requires immediate treatment.
- Primary sclerosing cholangitis (PSC) – inflammation of the bile ducts, which can lead to liver damage.
Crohn’s disease and cancer
Crohn’s disease can increase your risk of developing bowel cancer. This risk factor raises if you have had strictures in the gut, or you have had Crohn’s within your large bowel for a prolonged period (8+ years).
If you are identified as being at risk for developing bowel cancer, you will be invited to undergo regular colonoscopies to check for warning signs.
How is Crohn’s disease diagnosed?
A gastroenterologist (a doctor who specialises in gastrointestinal disorders) will be able to assess you for Crohn’s disease. They will take a detailed account of your symptoms and medical history, before performing a physical examination.
You may require further diagnostic tests, including:
- A blood test – to check for a high white blood cell count, which can be an indicator of inflammation.
- A stool test – to check your stool for bacteria and parasites, to rule out any infections causing your symptoms.
- CT scan – which creates detailed images of your digestive system so that inflammation can be assessed.
- MRI scan – to look for fistulas around the small intestine and anus.
- Endoscopy – a procedure that uses an endoscope (long, thin instrument with a light and camera) to see into the digestive system and examine areas of inflammation.
Crohn’s disease treatment
There is no cure for Crohn’s disease, but the condition can be managed so that symptoms are reduced or eliminated entirely. The main aim of treatment is to reduce the levels of inflammation within the gut.
What treatment you have depends on the severity of your symptoms and where your inflammation is in the gut.
Options include lifestyle changes, medication, and surgery.
Crohn’s disease medications
Medications for Crohn’s disease are usually targeted towards reducing inflammation. These include:
- Steroids – Steroids work quickly to reduce inflammation, making them ideal for flare-ups. However, they can only be used as a short-term treatment due to the risk of side effects. They are usually taken by mouth as tablets or capsules, but occasionally may be delivered via enemas, suppositories, or through an IV line.
- Immunosuppressants – Immunosuppressants help reduce the activity of your immune system, which in turn reduces inflammation. They can be used as a long-term treatment.
- Biological medicines (biologics) – These are a stronger type of medication that helps suppress inflammation. They may be used in people with moderate to severe Crohn’s disease, or where other treatments have not worked.
You may also take medication to help reduce symptoms. These include:
- anti-diarrhoeal drugs
- laxatives, to relieve constipation
- painkillers, like paracetamol
- antispasmodics, to reduce painful spasms and cramps within the gut
Crohn’s disease surgery
Crohn’s disease doesn’t typically require surgical intervention unless your condition is severe and not helped by medication, or if you have complications like strictures.
A resection is a surgical procedure where the inflamed tissue is removed, and the healthy parts of the bowel are re-stitched together. Sometimes, an ileostomy (where the end of the bowel is brought through an opening in the abdominal wall) is performed at the same time, so that the digestive system has time to recover from surgery. This is known as a stoma, and it is usually reversed once your digestive system has suitably recovered. However, if a large part of the bowel is removed, you may require a permanent stoma.
A strictureplasty is used to widen a narrowed section of the gut (a stricture). Strictures can occasionally occur as a complication of Crohn’s disease.
You may also need surgery to resolve a medical emergency due to your Crohn’s, such as a bowel obstruction or perforation.
Diet for Crohn’s disease
Some people with Crohn’s disease report that certain foods can cause flare-ups, although there is no evidence for this at present.
It is best for people with Crohn’s to follow a healthy, varied diet that includes a wide range of fruit, vegetables, nuts, seeds, proteins, and whole grains. They should avoid any foods high in salt, fat, and sugar, as well as ultra-processed foods.
You shouldn’t cut out any food groups unless advised by your GP or consultant; this is because you may miss out on key vitamins and nutrients.
Many people anecdotally report that alcohol causes flare-ups, so you may wish to limit your intake.
Liquid-only diet for Crohn’s disease
Occasionally, your consultant may recommend a special liquid-only diet, which allows the gut to rest and heal. It is more commonly used in children but can also be used in adults who are experiencing a flare-up but wish to avoid steroids. The prescribed liquid diet contains all the nutrients your body requires and is usually taken for 6 to 8 weeks.
