1993 Volume 171 Issue 2 Pages 145-151
MUNAKATA, A., NAKAJI, S., TAKAMI, H., NAKAJIMA, H., IWANE, S. and TUCHIDA, S. Epidemiological Evaluation of Colonic Diverticulosis and Dietary Fiber in Japan. Tohoku J. Exp. Med., 1993, 171(2), 145-151 - The incidence of colonic diverticulosis was examined in 5 hospitals geographically isolated from each other in Japan during the period between mid '70s and 1986. The incidence rapidly increased in all hospitals from 3.5-9.0% in mid '70s to 8.4-23.2% in 1986. The ratio of right-sided type colonic diverticulosis was approximately 70-80% in each hospital and the ratio did not fluctuate significantly during the period. Birth cohort analysis revealed that although the incidence of right-sided diverticula had increased with aging, in groups born in more recent decades right-sided diverticula appeared in younger age than other groups. It was suggested that environmental factors rather than congenital factors may cause the increase of the incidence of right-sided colon diverticula.