Inflammatory bowel disease

#### The bottom line A 21 year old woman presented to her general practitioner with tiredness and abdominal discomfort for the past year. She is treated for iron deficiency anaemia (attributed to menorrhagia) and for presumed irritable bowel syndrome. After hospital admission a few months later with suspected appendicitis, tests reveal vitamin B12 deficiency and raised inflammatory markers, prompting gastroenterology referral. Colonoscopy with terminal ileal biopsy confirms a diagnosis of Crohn's disease. Inflammatory bowel disease encompasses ulcerative colitis and Crohn's disease, both idiopathic chronic diseases of the gastrointestinal tract. Ulcerative colitis is characterised by diffuse inflammation affecting the mucosa of the colon only. Crohn's disease involves patchy transmural ulceration that can affect any part of the gastrointestinal tract. Around 5% of patients have features of both subtypes and are labelled inflammatory bowel disease "unclassified."1 #### How common is inflammatory bowel disease?