Crohn's disease causes inflammation of the digestive system. It is one of a group of diseases called inflammatory bowel disease. The disease can affect any area from the mouth to the anus. It often affects the lower part of the small intestine called the ileum.
Crohn's disease seems to run in some families. It can occur in people of all age groups but is most often diagnosed in young adults. Common symptoms are pain in the abdomen and diarrhea. Bleeding from the rectum, weight loss, joint pain, skin problems and fever may also occur. Children with the disease may have growth problems. Other problems can include intestinal blockage and malnutrition.