Is crohn's disease hereditary?

Yes: Crohn's disease is hereditary, but that does not mean if you have Crohn's your child will automatically get it. The risk of a child getting Crohn's from a parent is less than 10%. The risk does go up if both parents have inflammatory bowel disease.

Yes, but: The genetics of crohn's disease is very complicated so predicting risk of transmission to children, or predicting the risk for a sibling is very difficult. The risk of passing crohn's disease to a child is around 10%.

Yes: There is a genetic predisposition to developing Crohn's disease. That is not to say that everyone diagnosed will have a family history nor is it true that children born to patients will always get Crohn's disease (in fact the chances are less than 10%).

Yes. But not always: About 1/3 or IBD patient's will have a family history. There are many genes that have been isolated that are associated with Crohn's. That being said, there are environmental factors as well.