Inflammatory Bowel Disease

Inflammatory Bowel Disease

Definition/diagnostic criteria Inflammatory bowel disease (IBD) encompasses two major chronic conditions, Crohn’s Disease (CD) and Ulcerative Colitis (UC), characterised by intermittent inflammation of the gastrointestinal tract. Diagnosis typically involves a combination of clinical evaluation, endoscopy, histopathology, and radiology. Distinction between UC and CD is essential, given their varied treatment approaches and prognoses.

Epidemiology In the UK, the incidence of IBD is increasing. Approximately 300,000 individuals are affected by UC and CD. The onset can occur at any age, but peak incidence is between 15 and 30 years. Both genetic predispositions and environmental factors (such as smoking, diet, and microbial exposure) are implicated in its aetiology. UC shows a slight predominance in males, while CD is more common in females.


Clinical features Symptoms include persistent diarrhoea, abdominal pain, weight loss, and blood or mucus in the stool. Extra-intestinal manifestations may affect the skin, eyes, joints, and liver. The presentation can vary significantly between individuals and over time, with periods of remission and exacerbation.

Investigations Initial assessments involve blood tests to indicate inflammation (elevated CRP, ESR) and anaemia. Stool samples may exclude infections. Calprotectin, a stool marker, is used to differentiate IBD from irritable bowel syndrome (IBS) and monitor disease activity. Colonoscopy with biopsies remains the gold standard for diagnosis, differentiating between UC and CD and assessing the extent and severity of disease. Imaging, including MRI or CT enterography, is particularly useful for evaluating CD.

Treatment Management strategies involve controlling inflammation, maintaining remission, and addressing nutritional deficiencies. Treatment choice depends on disease type, location, severity, and response to previous treatments.

  1. Aminosalicylates (5-ASAs): Mainly used in UC for inducing and maintaining remission.
  2. Corticosteroids: Used for inducing remission in acute flare-ups but not suitable for long-term use due to side effects.
  3. Immunomodulators: Such as azathioprine or methotrexate, used for maintaining remission and reducing steroid dependency.
  4. Biologic therapies: Including anti-TNF agents (e.g., infliximab) and integrin receptor antagonists, used for patients with moderate-to-severe IBD, particularly those who do not respond to conventional therapy.
  5. Surgery: May be necessary for complications or severe disease, more commonly in CD than UC.

Diet and lifestyle adjustments, as well as psychological support, are also crucial aspects of management.

Prognosis: IBD is a chronic condition with periods of remission and relapse. Complications may include strictures, abscesses, fistulas (particularly in CD), and a slightly increased risk of colorectal cancer, especially in long-standing UC. With appropriate and timely treatment, most individuals maintain a good quality of life, although surgery or hospital admissions may be required. Regular monitoring and a collaborative approach between patients and healthcare providers are essential for effective management.

Published: 30th July 2022 Updated: 5th March 2024

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