The incidence rate of Crohn’s disease in Bahrain is comparable to the U.S.A and has increased for men and women in all age groups. In this paper by Zayyani et al, Crohn’s disease clusters were common among families and included up to 3 generations consistent with presence of a common source or common genetic factors.
https://academic.oup.com/ibdjournal/article/23/2/304/4347190