Crohn's disease

Crohn’s disease is a chronic (long-term) condition which causes inflammation of your digestive system, often triggering debilitating symptoms.

By Wallace Health I Medically reviewed by Adrian Roberts.
Page last reviewed: October 2018 I Next review due: October 2023

What is Crohn's disease?

Crohn’s disease is an inflammatory bowel disease, with inflammation affecting any section of your digestive system. The colon (large intestine) and the ileum (the small intestine’s final section) are the most commonly affected areas.

Men and women are equally likely to develop Crohn’s disease. It can occur at any age, although usually starts between 15 and 40.

Crohn’s disease causes different symptoms, including abdominal problems and problems around the anus such as an anal fistula or anal fissures. Crohn’s disease symptoms can vary from mild to severe and can flare-up (relapse) without warning. As a result, Crohn’s disease can disrupt your daily activities and make planning difficult.

Although there’s currently no cure for Crohn’s disease, symptoms can usually be managed. A combination of following a Crohn’s disease diet, medication and, occasionally, surgery, should help you lead a normal life.

How to tell if you have Crohn's disease

Crohn’s disease symptoms vary from person to person and can change over time. Depending on how active the disease is, your symptoms can vary in intensity and can develop slowly or very suddenly – or they may disappear only to flare-up again.

The most common Crohn’s disease symptoms include:

Talk to your doctor if you’re concerned about symptoms

You can book an appointment with a Spire private GP today.

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Diagnosis and tests for Crohn's disease

Your GP will check for inflammation, including bowel inflammation, by examining your abdomen and taking blood and stool samples.

Crohn’s disease is unpredictable and many of its symptoms are shared with other conditions so it can be difficult to diagnose. To confirm a diagnosis, your GP may refer you to a gastroenterologist - a consultant specialising in the digestive system.

Your consultant may recommend that you have:

  • A colonoscopy – a flexible tube with a camera attached to check for bowel inflammation
  • A biopsy – removal of a small sample of tissue from your intestine to check for inflammation or damage
  • An MRI or CT scan

Causes of Crohn's disease

The exact cause of Crohn’s disease isn’t known. However, it’s thought to be due to a combination of:

  • Genetics
  • The immune system reacting abnormally to bacteria in the digestive system
  • An unknown trigger - perhaps stress, diet, smoking or a virus

Common treatments for Crohn's disease

There are three main ways to manage your Crohn’s disease symptoms.


Your consultant may suggest changes to your diet which will relieve some of your Crohn’s disease symptoms, such as eating less fibre. They may refer you to a specialist dietitian, who’ll help you follow a Crohn’s disease diet.


Your consultant may prescribe:

  • Antibiotics
  • Steroids – to reduce inflammation
  • Biologics – a new generation of drug treatments
  • Immune suppressors
  • Symptom-relieving medication – such as painkillers or anti-diarrhoea pills


If dietary changes and medication fail to help, your consultant may recommend surgery. During surgery, damaged sections of your intestine or bowel are removed and the healthy sections connected together.

You may also need surgery to:

  • Clear an obstruction in your digestive system
  • Drain an abscess
  • Close a fistula - a painful channel that can form, connecting two areas of bowel together near the anus