My partner has crohn's disease and i was wonder what could be the chance of it passing to our children ?

Approximately 10%: Crohn's disease (cd) is a complex disease involving both genetics and environment. With regard to genetics and heritability, the likelihood that a child with one parent affected with cd will get the disease sometime during their life is about 10%. New knowledge is gained every day on the genetics of cd so ask your partner's GI doc about new findings and the possibility of new genetic tests.

Yes: Crohn's disease has many genetic components so it is too complicated to say for sure what the risk is that your children will get crohns. However the risk is definitely elevated above the general population--perhaps a 5-10 fold risk above someone else of your same ethnic background. No screen is necessary but if a child has chronic GI complaints, get them checked out.