What is Crohn’s disease?

Crohn’s disease is a chronic condition that causes inflammation anywhere in the digestive system. It is a form of inflammatory bowel disease. The cause remains unknown, although it can tend to run in families.


This will depend on the anatomical site involved, as inflammation due to Crohn’s disease can occur anywhere from the mouth all the way to the anus (bottom). The part of the small intestine known as the terminal ileum is the commonest area affected. Possible symptoms include abdominal pain, weight loss, diarrhea, constipation, rectal bleeding and mucus, anal abscesses/fistulas, mouth ulcers and vomiting. Occasionally, other areas of the body may show signs of inflammation, including skin rashes, pain/irritation around the eyes or painful and swollen joints.


These may include blood tests, stool tests, rigid sigmoidoscopy in the outpatient clinic, scans (either CT or MRI), endoscopy, where a flexible camera is used to investigate part of the bowel and potentially take biopsies to help with diagnosis (colonoscopy, flexible sigmoidoscopy and/or upper GI endoscopy may be recommended by your consultant) or occasionally examination of the anal region under general anaesthetic in order to control infection and assess anatomy.


Generally, initial treatments will be aimed at controlling inflammation with medication (including steroids, 5-ASA drugs, immunosuppressive drugs such as azathioprine, methotrexate and 6-MP, or biologic anti-TNF agents such as Infliximab and Humira), sometimes in combination with dietary changes.

If the medication is not sufficient, or side-effects develop, then surgery may be required. In the setting of Crohn’s disease, your surgeon will always be aiming to preserve as much of the bowel as possible. However, removal of a section of the bowel (resection) may be required, or a narrowed area may be able to be widened rather than removed (known as strictureplasty). In the anal region, surgical treatment or control of anal abscess and fistula may be needed, with drainage sutures, known as setons, commonly used.

Surgery does not provide a cure for Crohn’s disease, but can often provide long periods of time with symptomatic relief and disease remission.

Once a diagnosis of Crohn’s disease has been made, it is strongly advisable to stop smoking, as smoking is a significant risk factor for disease persistence and recurrence.