Crohn's disease is a long-term inflammatory bowel disease that can affect any part of the digestive tract, with common symptoms including diarrhea, abdominal pain, fever, and weight loss. While the exact cause is unknown, it is thought to be an autoimmune disorder attacking the intestines. Diagnosis involves a colonoscopy, and treatment ranges from antidiarrheal drugs for mild cases to corticosteroids for acute attacks, with many patients eventually requiring surgery that can shorten life expectancy over time.