Crohn's disease is a chronic inflammatory bowel disease (IBD) that causes inflammation and irritation in the digestive tract. It can affect any part of the gastrointestinal tract, from the mouth to the anus, but most commonly involves the small intestine and the beginning of the large intestine (colon)

. The inflammation caused by Crohn's disease can affect all layers of the intestinal walls and often occurs in patches, with healthy tissue in between. This inflammation leads to symptoms such as abdominal pain, diarrhea, weight loss, rectal bleeding, and fatigue. Other complications may include anemia, skin rashes, arthritis, eye inflammation, and bowel obstruction. People with Crohn's disease are also at increased risk for colon and small bowel cancer

. The exact cause of Crohn's disease is unknown, but it is believed to result from an abnormal immune response in genetically susceptible individuals, possibly triggered by environmental and bacterial factors. It is not considered a classic autoimmune disease but involves immune system dysfunction. Genetics play a significant role, with over 70 genes implicated, and smoking increases the risk substantially

. Crohn's disease is a lifelong condition with periods of flare-ups and remission. While there is no cure, treatments aim to manage symptoms and maintain remission, allowing most people to lead active lives. Treatment may include medications to reduce inflammation and immune response, dietary management, and sometimes surgery to remove damaged sections of the intestine

. In summary, Crohn's disease is a chronic inflammatory disorder of the digestive tract characterized by patchy inflammation, causing a range of gastrointestinal and systemic symptoms, with no known cure but manageable through medical and surgical interventions.