EDITORIAL COMMENT The incidence of Crohn's disease in Norway has been studied for the eight-year period 1956-63. A total of 73 cases of typical Crohn's disease was reported. The average annual rate per 1,000,000 population was 2-6 and the incidence during the period under review may have risen. There was no sex difference. The incidence was low in the youngest age groups. The rate did not vary ...