Crohn's disease is an inflammatory bowel disease that can affect any part of the gastrointestinal tract, most commonly the end of the small intestine (ileum) and the colon. The cause is unknown, but it may be related to the immune system, genetics, and environment. People with Crohn's are more susceptible to intestinal infections that can lead to complications. There is no cure for Crohn's, but symptoms can be managed, and remission can be achieved with effective treatment. Untreated Crohn's can progress and cause serious complications. Treatment should be consistent, including a healthy diet and regular medication. Untreated Crohn's can lead to many complications, such as intestinal obstruction, fistulas, anal fissures, malnutrition, osteoporosis, colon cancer, arthritis, mouth ulcers, kidney stones, eye and skin problems, among others. Early treatment and regular follow-ups are very important.