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. 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.