This book is devoted to research on Crohn's disease (also known as regional enteritis)which is a chronic, episodic, inflammatory bowel disease (IBD) and is generally classified as an auto-immune disease. Crohn's disease can affect any part of the gastrointestinal tract from mouth to anus; as a result, the symptoms of Crohn's disease vary among afflicted individuals. The disease is characterised by areas of inflammation with areas of normal lining between in a symptom known as skip lesions. The main gastrointestinal symptoms are abdominal pain, diarrhoea (which may be bloody, though this may not be visible to the naked eye), constipation, vomiting, weight loss or weight gain. Crohn's disease can also cause complications outside of the gastrointestinal tract such as skin rashes, arthritis, and inflammation of the eye. Although the cause of Crohn's disease is not known, it is believed to be an auto-immune disease that is genetically linked. The highest relative risk occurs in siblings, affecting males and females equally. Smokers are three times more likely to get Crohn's disease. Unlike the other major types of IBD, there is no known drug based or surgical cure for Crohn's disease. Treatment options are restricted to controlling symptoms, putting and keeping the disease in remission and preventing relapse.