Diagnosis and treatment of inflammatory bowel disease.

Patients with inflammatory bowel disease (IBD) may previously have received a diagnosis of irritable bowel syndrome and there may be a delay in making the correct diagnosis. This is particularly the case in patients with ileal Crohn's disease and those under 40. Diagnosis of IBD involves endoscopy and biopsy. Histology may not be available – for example in small bowel Crohn's disease – and in this situation, typical radiological appearances help make the diagnosis. Crohn's disease can affect any part of the gastrointestinal tract – most commonly the terminal ileum or colon. Perianal involvement is also common. Intestinal inflammation in Crohn's disease can extend transmurally. Ulcerative colitis almost always affects the rectum with a variable proximal extent and continuous distribution. Inflammation affects the mucosa only. Approximately 25% of people with IBD will have extra-intestinal manifestations of the disease, involving skin, eyes, joints or the liver. There is an increased risk of colorectal cancer in patients with ulcerative colitis estimated at 2% at 10 years, 8% at 20 years and 18% at 30 years. It is important to be aware of infection risk in IBD both due to the disease itself and the impact of treatment. Flu vaccination should be offered to patients with IBD.