CROHN'S DISEASE - An inflammatory disease of the gastrointestinal tract of unknown cause. The peak incidence of onset of this disease is between 15 and 25 years of age. Crohn's also occurs in later years between the ages of 55 and 60. Common symptoms include recurrent abdominal pains, fever, nausea, vomiting, weight loss, and diarrhea which is occasionally bloody. Complications include gastrointestinal bleeding, fistulas, and anal fissures. Treatment includes anti-inflammatories and corticosteroids. Surgery is successful in a select few.