The facts you need to know about Crohn's disease (CD)

Facts-you-need-to-know-CD

What is CD and how does it relate to IBD?

You may hear the terms CD and IBD used interchangeably, but they are not quite the same thing. IBD, or inflammatory bowel disease, describes inflammation of the bowel caused by two conditions: Crohn’s disease (CD) and ulcerative colitis (UC).1

Facts UC Aus people map Callout

While UC causes inflammation in the inner lining of the large intestine and rectum, CD can inflame any part of the digestive tract from the mouth to the anus and can impact the full thickness of the tract wall. Both conditions have some symptoms in common.1

 

The digestive tract3

This graphic is for illustrative purposes only. CD is not limited to any particular gender.

 

How does CD affect people?

IBD can develop at any age, but usually first appears in people aged 15 to 30. The symptoms of CD can vary between people and can even come and go over time depending on how inflamed the bowel is.1

The periods when CD symptoms are heightened are called flares and periods when they ease are called remission. You can read more about this on our Identifying Flares and Triggers page. The main symptoms of CD can include:4,5

facts 1.1.1_intestines@2x

 

 

Persistent diarrhoea

facts 1.1.2_blood@2x

 

 

Blood or mucus in stool/poo

facts 1.1.3_cramps@2x

 

 

Belly pain or cramps

facts 1.1.4_toilet@2x

 

 

Urgent need to go to the bathroom

facts 1.1.5_tiredness@2x

 

 

Extreme tiredness

facts 1.1.6_scale@2x

 

 

Loss of appetite and weight loss

But these are just the obvious symptoms. Living with CD can affect people’s quality of life in many different ways; it may affect one's ability to work or impact social engagements and personal relationships. It’s also common for people living with the symptoms of CD to experience anxiety and depression as a result.6

If you are experiencing this, you are not alone and support is available. It is important to seek support if CD is affecting your quality of life and your overall health and well-being.

Visit our Communicating and Getting Support page for more information on who to seek support from.

 

What causes CD?

CD is an ‘autoimmune’ condition. This means the immune system mistakenly attacks the bowel tissue, causing it to become inflamed and resulting in the symptoms of CD.5,7

The exact cause of CD is still unknown, but research shows that genetics, infections, and other environmental factors may play a role. Environmental factors can include things like eating a diet high in fat, sugar and processed foods (known as a Western diet), as well as smoking.5,7

It's important to note that while stress and certain foods can sometimes trigger symptoms, CD is not caused by diet or stress alone. Visit Diet page to learn more about diet for CD.5

References: 1. Gastroenterological Society of Australia. Factsheet: Inflammatory Bowel Disease (IBD). Available from: gesa.org.au/ Accessed: August 2025. 2. Crohn’s and Colitis Australia. Crohn’s disease. Available from: crohnsandcolitis.org.au/about-crohns-colitis/crohns-disease Accessed: August 2025. 3. National Institute of Diabetes and Digestive and Kidney Diseases. Your Digestive System & How it Works. Available from: niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works Accessed: August 2025. 4. Crohn’s and Colitis Foundation. Signs and symptoms of Crohn’s disease. Available from: crohnscolitisfoundation.org/what-is-crohns-disease/symptoms Accessed: August 2025. 5. Healthdirect. Crohn’s disease. Available at: healthdirect.gov.au/crohns-disease Accessed: August 2025. 6. Gastroenterological Society of Australia. Mental Health and IBD. Available from: gesa.org.au/ Accessed: August 2025. 7. Petagna L et al. Biol Direct 2020;15:23. AC-005092-00. AU-RNQ-250038. August 2025.