title: Natural history of outpatient-onset ischemic colitis compared with other lower gastrointestinal bleeding: a long-term cohort study.
abstract: OBJECTIVE
  The long-term clinical course of outpatient-onset ischemic colitis remains unknown. Our aims are to elucidate the in- and out-of-hospital clinical outcomes of ischemic colitis and compare them with those of lower gastrointestinal bleeding (LGIB).
  
  
  METHODS
  A cohort of 370 outpatients was hospitalized for ischemic colitis (n = 57) or other LGIB (n = 313). All patients had undergone colonoscopy. During hospitalization, the need for transfusion or interventions, further bleeding, mortality, and length of hospital stay were measured. After discharge, long-term recurrence and mortality were analyzed by the Kaplan-Meier method.
  
  
  RESULTS
  Colonoscopy revealed that 88% of ischemic colitis cases were left sided. Compared with other LGIB, ischemic colitis cases had significantly lower transfusion requirements (p < 0.01), further bleeding (p = 0.02), endoscopic intervention (p < 0.01), and shorter hospital stay (p = 0.03). No significant differences between the groups were noted in the need for surgery, angiographic procedures, or mortality during hospitalization. During a mean follow-up of 22 months, rebleeding was significantly lower (log-rank test; p < 0.01) in ischemic colitis cases (5.3%) than in other LGIB cases (19.4%) after discharge. During the mean follow-up period of 29 months, 1 patient (1.8%) with ischemic colitis and 18 patients (5.8%) with other LGIB died (log-rank test; p = 0.41).
  
  
  CONCLUSIONS
  Outpatient-onset ischemic colitis patients usually had left-sided colitis, recovered with conservative short-term treatment and had lower transfusion requirements and further bleeding compared with other LGIB patients. After discharge, patients with outpatient-onset ischemic colitis had lower recurrence over the long term than other LGIB patients.
authors.affiliation: Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine (NCGM), 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan, nnagata_ncgm@yahoo.co.jp.
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Nagata
authors.forename: Ryota
authors.initials: R
authors.lastname: Niikura
authors.forename: Tomonori
authors.initials: T
authors.lastname: Aoki
authors.forename: Takuro
authors.initials: T
authors.lastname: Shimbo
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kishida
authors.forename: Katsunori
authors.initials: K
authors.lastname: Sekine
authors.forename: Shohei
authors.initials: S
authors.lastname: Tanaka
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Okubo
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Watanabe
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sakurai
authors.forename: Chizu
authors.initials: C
authors.lastname: Yokoi
authors.forename: Junichi
authors.initials: J
authors.lastname: Akiyama
authors.forename: Mikio
authors.initials: M
authors.lastname: Yanase
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
authors.forename: Naomi
authors.initials: N
authors.lastname: Uemura
mesh_terms: D000368:Aged; D015331:Cohort Studies; D017091:Colitis, Ischemic / Q000150:complications / Q000401:mortality / Q000473:pathology*; D003113:Colonoscopy; D018450:Disease Progression; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000150:complications / Q000473:pathology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D010351:Patient Discharge; D012008:Recurrence; D013997:Time Factors; D016896:Treatment Outcome