Crohn’s disease (CD) is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract from the mouth to the anus. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, and weight loss. It should be differentiated from irritable bowel syndrome and ulcerative colitis. The finding of an antibody to Saccharomyces cerevisiae (ASCA) can help confirm the diagnosis of CD.