I actually have been a participant in the Nurses Health Study since it began in 1976 (I guess nurses are good at returning survey responses). Lots of long term data have been collected over the decades. I am currently in a side study about gestational diabetes and long term diabetes risk. Anyway, I digress.
The main point I got from this article was specifically that birth control pills did not cause Crohn's, but were more like a trigger for those genetically susceptible. I found it interesting that the same was not found true for UC. Another indicator that whileUC and Crohn's are both in the IBD spectrum, they have distinct disease paths.
Jan