Unfortunately in my family we almost all have it.
Grandad and Grandma ~ Grandad has it.
Dad, Aunt, Uncle ~ Aunt and Uncle have it.
Brother, Sister, Me, cousins ~ I have something, sister has IBS, One female cousin has Crohn's. There is also chances of two more cousins having it because of the little routine our family seems to have with timings of our symptoms, the symptoms and how it all pans out.
But I know a lot of people on this site are completely alone with their illness and have no relatives that have IBD too.