title: Recent trends in diverticulosis of the right colon in Japan: retrospective review in a regional hospital.
abstract: OBJECTIVE
  Diverticulosis of the right colon has been increasing in the Far East; however, a considerable proportion of these patients includes cases of solitary right-sided diverticular disease. This study aimed to determine whether the incidence of such solitary diverticula (defined as 1 or 2 diverticula in this study) and multiple (3 or more) diverticula of the right colon is increasing in Japan.
  
  
  METHODS
  A total of 13,947 consecutive barium enema examinations, performed in the period from 1982 to 1997, were reviewed. Changes in the frequency (detection rate) and number of diverticula across time and with aging of three types of diverticula, right-sided, left-sided, and bilateral, were investigated, with special interest in those patients with one or two diverticula of the right colon.
  
  
  RESULTS
  Right-sided and bilateral diverticula have increased in frequency across time; however, left-sided diverticula have not. Patients with one or two diverticula in the right colon of right-sided disease, unexpectedly, have increased across time in both genders, and patients with three or more diverticula in the right colon of right-sided disease have shown an increase in males. The number of diverticula of the right colon showed no increase across time or with aging.
  
  
  CONCLUSIONS
  Diverticulosis of the right colon, both solitary and multiple, has been increasing steadily in Japan; therefore, diverticulitis and bleeding diverticula of the right colon may continue to increase. Diverticula of the right colon might be an acquired disease and self-limiting in development, because the frequency did not increase substantially in the elderly and because the number changed little across time and with aging.
authors.affiliation: First Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Miura
authors.forename: S
authors.initials: S
authors.lastname: Kodaira
authors.forename: T
authors.initials: T
authors.lastname: Shatari
authors.forename: M
authors.initials: M
authors.lastname: Nishioka
authors.forename: Y
authors.initials: Y
authors.lastname: Hosoda
authors.forename: T K
authors.initials: TK
authors.lastname: Hisa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D004241:Diverticulum, Colon / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies