Crohn's disease, Crohn disease, or Leśniowski-Crohn disease is an illness that causes the intestines, or other parts of the digestive tract (the parts of the body food goes through), to become swollen, and sometimes develop ulcers (holes). People with Crohn's disease often have pain in the gut, diarrhea, vomiting, and weight loss. Crohn's can also cause skin rashes, arthritis, and swollen eyes.
Nobody knows exactly what causes Crohn's disease. In the disease, the person's body attacks itself. The immune system attacks healthy parts of the digestive tract. This causes inflammation, or swelling, in the digestive tract. Therefore, Crohn's disease is one of two inflammatory bowel diseases and one of many autoimmune diseases.
Like many other autoimmune diseases, Crohn's disease seems to be connected to the person's genes. People whose brothers or sisters have the disease are the most likely to get it. Men and women are both just as likely to get Crohn's disease.