The exact cause of inflammatory bowel disease is not known. The following are the postulates.

• Infection
• Allergy
• Immune system
• Abnormal immune response to
  • Bacteria, virus, food
  • Environment
• Higher in people living in cities/ industrialized areas
• Diet higher in fat or refined food
• Heredity
• 20% have a relative suffering from similar disease .
• May be related to gene/s

Intestinal bacteria: In the intestine there are large number of bacteria, which le in harmony with body. Certain bacteria are protective. In inflammatory bowel disease, there is change in the bacterial population called as dysbiosis. Certain bacterial species, which are useful, are reduced. Bacteria interact with genes