Purposes: Colonoscopic evidence of epidemiological trends in diverticulosis and diverticular bleeding is scarce. We evaluated trends in diverticular disease and associated factors over 9 years.
Methods: Twenty-eight thousand one hundred ninety-two patients who underwent colonoscopy at an emergency hospital were reviewed from an electronic endoscopy database. Diverticula were classified as right-sided, left-sided, and bilateral types, and time trends in the proportion in diverticulosis, type, and diverticular bleeding were determined. Associations of age (≤39, 40-59, and ≥60 years), sex, and year increase with disease and odds ratios were estimated using logistic regression.
Results: Diverticulosis was identified in 6,150 patients (20.3 %; mean age, 67.6 years) and was predominantly right-sided (48.0 %). Diverticular bleeding was found in 427 (1.5 %; mean age, 69.7 years) and was predominantly bilateral (47.0 %). Proportion of colonic diverticulosis increased significantly (P < 0.01 for trend) from 66.0 % (1,424/2,157) in 2003 to 70.1 % (2,914/4,159) in 2011 and was associated (P < 0.01) with an increased number of patients aged ≥60 years. Proportion of diverticular bleeding increased significantly (P < 0.01 for trend) from 1.02 % (22/2,157) in 2003 to 1.67 % (69/4,159) in 2011 and was associated (P = 0.04) with an increased number of patients aged 40-59 years. Diverticulosis, right and bilateral type, and diverticular bleeding were independently associated with the 9-year trend after adjustment by age and sex.
Conclusions: Colonic diverticulosis and diverticular bleeding are prevalent and increasing in Japan. Given the significant association of age with this trend, both diseases can be expected to increase for decades to come.